North West Adelaide Health Study a biomedical cohort research study of randomly selected Adelaide adults Stage 2 Key Findings
This work is copyright. It may be reproduced and the Population Research and Outcome Studies (PROS) Unit welcomes requests for permission to reproduce in the whole or in part for work, study or training purposes subject to the inclusion of an acknowledgment of the source and not commercial use or sale. PROS will only accept responsibility for data analysis conducted by PROS staff or PROS supervision. Published May 2007 by the South Australian Department of Health Population Research and Outcome Studies Unit PO Box 287 Rundle Mall 5000 South Australia, Australia The National Library of Australia Cataloguing-in-Publication entry: South Australia. Population Research and Outcome Studies. North West Adelaide health study : a biomedical cohort research study of randomly selected Adelaide adults. ISBN 9780730898986 (pbk.). 1. Health surveys - South Australia - Adelaide. I. South Australia. Dept. of Health. II. Title. 614.4294231 Suggested citation: Population Research and Outcome Studies Unit. North West Adelaide Health Study: Stage 2 Key Findings. Department of Health; Adelaide, May 2007. This document is one of a series of reports concerning Stage 2 of the North West Adelaide Health Study. Please see website for other reports in the series - www.health.sa.gov.au/pros/ CONTACT DETAILS: Population Research & Outcome Studies Unit South Australian Department of Health PO Box 287 Rundle Mall Level 8 CitiCentre, 11 Hindmarsh Square, Adelaide SA 5000 Telephone (08) 8226 7042 Facsimile (08) 8226 6244 Email: pros-nwahs@health.sa.gov.au Acknowledgment is made of the contribution to the success of the study by research, clinic and recruiting staff, and for the generosity of the NWAHS participants in the giving of their time and effort.
Table of Contents Foreword... 5... 7 The North West Adelaide Health Study... 7 Methodology... 8 Key Findings... 9 Chronic Conditions... 9 Modifiable Risk Factors... 10 Health Outcomes... 12 Chronic Conditions... 13 Asthma... 14 Chronic obstructive pulmonary disease....... 15 Cardiovascular disease... 16 Diabetes........ 17 Mental health condition...... 18 Depression.... 19 Psychological wellbeing..... 20 Renal disease... 21 Musculoskeletal Conditions... 23 Arthritis... 24 Back pain...... 25 Foot pain.... 26 Hip pain..... 27 Knee pain...... 28 Osteoporosis..... 29 Shoulder pain....... 30 Risk Factors... 31 Alcohol...... 32 Blood pressure......... 33 Body mass index...... 34 Cholesterol.... 35 Physical activity.... 36 Smoking..... 37 Waist circumference....... 38 Waist hip ratio... 39 Health Outcomes... 41 Health service use... 42 Medications............. 43 Overall health status...... 44 Quality of life..... 45 References... 46 Study Team... 47 3
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Foreword Chronic diseases are the epidemic of the 21 st century. They are presenting South Australia with a staggering economic and quality of life burden, and major prevention and management challenges. The North West Adelaide Health Study is an important research activity which is providing much of the evidence for the magnitude of the chronic disease problem and relevant risk factors. The study is providing the baseline data to enable measurement of the effectiveness of strategies in preventing and managing chronic disease. The results presented in this report are an important resource available to health planners, service providers, policy makers and community members and should stimulate the whole community to develop sustainable strategies to reduce the chronic disease burden. This major research project is an important collaboration between government (South Australian Department of Health), health services (The Queen Elizabeth Hospital, Lyell McEwin Hospital, and Institute of Medical and Veterinary Science) and academia (The University of Adelaide and University of South Australia). We are also very grateful to the participants of the study and the team of researchers and clinic staff, who so willingly gave their time, commitment, and expertise, which is essential to the success of the study. Many results presented in this report have never been available in South Australia or Australia before. Stage 1 of the study provided baseline information on the burden of priority chronic diseases and risk factors, and the proportion of people who had these conditions but had not been diagnosed. The longitudinal nature of the cohort study means that following Stage 2, we now have valuable information about the number of people who are developing these conditions over time, and the factors that increase the risk of developing chronic disease. The results show that the concern expressed about chronic disease and the associated risk factors are indeed true and the situation calls for urgent and sustained action. In addition, there are many positive stories in the results, particularly regarding people adopting healthier lifestyles. While chronic disease is often considered a condition of older age, and people are increasingly living longer, it is important that the risk factors are addressed early. Chronic disease requires a large share of our limited health budget. With the ageing of the South Australian population, urgent action is being undertaken. This report, and the subsequent analyses that will be conducted, are fundamental in providing the evidence so that our valuable health dollars are spent appropriately and our most valuable asset our community live long, healthy and productive lives. Professor Richard Ruffin Principal Investigator, North West Adelaide Health Study Deputy Head, Discipline of Medicine, University of Adelaide Respiratory Physician, The Queen Elizabeth Hospital Campus, Central Northern Adelaide Health Service 5
The North West Adelaide Health Study The North West Adelaide Health Study (NWAHS) is a longitudinal representative cohort of over 4000 randomly selected adults aged 18 years and over, originally recruited from the northern and western regions of Adelaide. It is an ongoing epidemiological research collaboration between the South Australian Department of Health, The University of Adelaide, the University of South Australia, The Queen Elizabeth Hospital, the Lyell McEwin Hospital and the Institute of Medical & Veterinary Science. The study focuses on priority health conditions and risk factors that have been identified due to the significant burden placed on the community in terms of health, social, economic and quality of life costs. A major challenge for epidemiologists and public health professionals is to paint the chronic disease picture in new and innovative ways that may galvanise action by researchers, governments and communities. Identifying and describing specific population groups at risk may assist in maximizing the effectiveness of strategies for the prevention, early detection, and management of chronic conditions. This report presents an overview of the initial key findings from Stage 2 of the study, followed by a one page précis of the main results pertaining to prevalence and incidence estimates for each chronic condition, modifiable risk factor and health outcome. The complete Stage 2 incidence reports are available at www.health.sa.gov.au/pros/ or www.nwadelaidehealthstudy.org/. Participants were recruited to Stage 1 of the study between 2000 and 2003, and returned for their Stage 2 clinic visit between 2004 and 2006. The main objective of Stage 1 of the cohort was to establish urgently needed baseline self-reported and biomedically measured information on diabetes, asthma and COPD and health-related risk factors in terms of those who were at risk of these conditions, those who had these conditions but had not been diagnosed, and those who had previously been diagnosed. Identifying those categories of disease along a continuum (Figure 1) provides a clearer statement of disease burden and presents evidence for opportunities for effective intervention, health service use and health policy. Improved health status / Deteriorating health status Not at risk At risk Previously undiagnosed Diagnosed without comorbidity Diagnosed with comorbidity Death Prevention Delay / Early Detection Prevention / Delay / Early Detection / Care Figure 1: Chronic disease continuum 7
Methodology Stage 1 All households in the northern and western areas of Adelaide with a telephone connected and a telephone number listed in the Electronic White Pages were eligible for selection in the study. Selected households were sent an approach letter and brochure informing them about the study. Within each household, the person who had their birthday last and was aged 18 years and over, was selected for interview. Interviews were conducted using computer-assisted telephone interview (CATI) technology. Respondents to the telephone interview were asked a number of health-related and demographic questions, and were invited to attend a clinic for a 45 minute appointment at either The Queen Elizabeth Hospital or the Lyell McEwin Hospital. Study participants were sent an information pack about the study, including a self-report questionnaire about a number of chronic conditions and healthrelated risk factors. During the clinic visit, height, weight, waist and hip circumference, and blood pressure were measured. Lung function and allergy skin prick tests were conducted and a fasting blood sample was taken to measure glucose, tryglycerides, total cholesterol, high density lipid (HDL), low density lipid (LDL), and glycated haemoglobin (HbA1c). Consent was obtained from participants to link to their Medicare Australia data. In Stage 1 there were 4060 participants (49.4% of the eligible sample, and 69.4% of those who completed the telephone interview) who attended the clinic. Stage 2 Participants were invited to attend the clinic for Stage 2 in a telephone interview that also obtained demographic and health-related information. Of the original living cohort, 3564 (90.1%) participants provided some Stage 2 information, and 3206 (81.0%) attended the clinic for their second visit. In addition to the measurements taken at Stage 1 (except skin prick tests), musculoskeletal tests were conducted including hand grip strength, hand photographs, shoulder range of movement, and foot pain. In addition, the urine sample supplied by the participant was tested for albumin and creatinine relating to kidney function. Participants aged 50 years and over were also offered a DEXA scan (dual-energy x-ray absorptiometry) to measure their bone density, and fat and lean body mass. Further details on the study methodology and results from Stage 1 can be downloaded from the NWAHS website (www.nwadelaidehealthstudy.org/), the Population Research and Outcome Studies (PROS), Department of Health website (www.health.sa.gov.au/pros/), or can be obtained by contacting the PROS Unit on freecall 1800 635 352. 8
Key Findings Chronic Conditions The following key findings highlight estimates obtained from the North West Adelaide Health Study (NWAHS). As the population of the north west Adelaide region is largely representative of South Australia as a whole, estimates have been extrapolated to provide incidence rates for the whole state. A limitation of the estimates in this report is that they have not been age-sex standardised. This means that increases in disease prevalence that are associated with ageing of the population have not been taken into account. Definitions Prevalence: Stage 1 data provide the prevalence of chronic conditions, risk and preventive factors, and health outcomes. Prevalence is a measure of the number, or proportion, of people with a certain condition in a population at a given point in time. Incidence: Incidence is the number of new cases of a certain condition in a population within a period of time. Asthma One in 8 adults (12.5%) had asthma at Stage 1. This increased to 16.2% of Stage 2 participants. The annual incidence of asthma is 24.6 people per 1000 in the adult population. Chronic obstructive pulmonary disease (COPD) One in 26 adults (3.9%) had COPD at Stage 1. This proportion did not significantly change by Stage 2 (4.8%). The annual incidence of COPD is 6.1 people per 1000 in the adult population. Cardiovascular Disease (CVD) One in 16 adults (6.2%) had CVD (heart attack, stroke, or angina) at Stage 1. The total proportion of participants reporting CVD had not significantly changed by Stage 2, although 2.3% of participants who did not have CVD at Stage 1 had developed it by Stage 2. The annual incidence of CVD is 5.6 people per 1000 in the adult population. This means that approximately 6,200 South Australian adults develop CVD each year. Diabetes One in 15 adults (6.6%) had diabetes at Stage 1. This proportion did not significantly change by Stage 2 (7.2%). The annual incidence of diabetes is 6.8 people per 1000 in the adult population. This means that approximately 7,500 South Australian adults develop diabetes each year. 9
Kidney health One in 18 Stage 2 participants (5.5%) had microalbuminuria or macroalbuminuria. One in 9 Stage 2 participants (11.5%) had chronic kidney disease. Mental Health One in 7 adults (13.6%) had a current diagnosed mental health condition at Stage 1. This increased to 16.1% of Stage 2 participants. The annual incidence of a current mental health condition is 22.9 people per 1000 in the adult population. This means that approximately 23,500 South Australian adults are diagnosed with a current mental health condition each year. Among Stage 2 participants, one in 8 had depression (as measured by the CES-D) and one in 7 had high or severe psychological disturbance (as measured by the GHQ-12). Musculoskeletal conditions One in 28 Stage 2 participants aged 50 years and over (3.6%) had osteoporosis, and a further one in 7 (15.0%) had osteopenia. One in 5 Stage 2 participants (21.4%) had arthritis. One in 6 Stage 2 participants (16.0%) reported knee pain. One in 3 Stage 2 participants (30.3%) had ever had pain or aching in their low back either at rest or when moving on most days for at least a month. One in 6 Stage 2 participants (17.6%) reported foot pain. One in 4 Stage 2 participants (22.3%) reported that they had pain or stiffness in their shoulder on most days for at least a month. One in 11 Stage 2 participants (9.2%) reported hip pain and one in 13 Stage 2 participants (7.7%) reported hip stiffness. Alcohol Modifiable Risk Factors One in 16 adults (6.1%) consumed alcohol at intermediate to very high levels of risk at Stage 1. The total proportion who consumed alcohol at risky levels had not significantly changed by Stage 2, although 3.6% of non or low risk drinkers at Stage 1 had increased their alcohol risk by Stage 2. The annual incidence of intermediate to high risk drinking is 9.6 people per 1000 in the population. This means that approximately 10,700 South Australian adults become intermediate/high risk drinkers each year. There are approximately 800 adults each year who become low or no risk drinkers. 10
Blood Pressure One in 4 adults (26.8%) had high blood pressure at Stage 1. The total proportion with high blood pressure did not significantly change by Stage 2 (25.8%), although 14.0% of participants with normal blood pressure at Stage 1 had developed high blood pressure by Stage 2. The annual incidence of high blood pressure is 33.6 people per 1000 in the population. This means that approximately 29,200 South Australian adults develop high blood pressure each year. There are approximately 9,800 adults who reduce their blood pressure from high to normal levels each year. Cholesterol One in 3 adults (36.3%) had high cholesterol at Stage 1. This increased to 40.6% at Stage 2. The annual incidence of high cholesterol is 45.4 people per 1000 in the population. This means that approximately 34,400 South Australian adults develop high cholesterol each year. There are approximately 12,500 adults each year whose cholesterol is reduced from high to normal levels. Obesity One in 4 adults (27.0%) had a body mass index (BMI) of at least 30kg/m 2 at Stage 1. This proportion had not significantly changed by Stage 2 (29.3%). The annual incidence of obesity, as measured by BMI, is 18.6 people per 1000 in the population. This means that approximately 16,100 South Australian adults develop obesity each year. There are approximately 3,400 adults each year who reduce their BMI and are no longer classified as obese. More than one in 2 adults (58.1%) had a waist circumference greater than 95cm for men and 80cm for women at Stage 1. This increased to 63.9% at Stage 2. When measured using waist circumference, the annual incidence of obesity is 30.8 people per 1000 in the population, which is 15,300 each year. One in 6 adults (16.4%) had a waist hip ratio greater than 1.0 for men and 0.8 for women at Stage 1. This increased to 23.3% at Stage 2. When measured using waist hip ratio, the annual incidence of obesity is 34.2 people per 1000 in the population, which is 34,000 each year. Physical Activity One in 4 adults (28.1%) were sedentary, and undertook minimal physical activity at Stage 1. The proportion who were sedentary did not significantly change by Stage 2 (28.9%). The annual incidence of decreasing physical activity levels from active to sedentary is 41.5 people per 1000 in the population. This means that approximately 35,400 adults each year reduce their activity levels from active to sedentary. The annual incidence of increasing physical inactivity from sedentary to low, moderate or high levels of activity is 37.5 people per 1000 in the population. This means that approximately 12,500 South Australian adults increase their activity levels from being sedentary each year. 11
Smoking One in 4 adults (24.4%) were current smokers at Stage 1. The total proportion who were current smokers decreased to 20.1% at Stage 2, although 3.3% of non or ex smokers at Stage 1 became current smokers at Stage 2. The annual incidence of taking up smoking is 6.9 people per 1000 in the adult population. The annual incidence of quitting smoking is 16.3 people per 1000 in the adult population. Health Service Use Health Outcomes In Stage 1, 94.0% of participants reported using a health service at least once in the last 12 months. This proportion had not significantly changed by Stage 2 (94.7%). Medications One in 3 (31.5%) participants at Stage 2 reported that they were not taking any medications. One in 5 (19.0%) were taking one medication, one in 7 (14.6%) were taking two medications, and one in 3 (34.8%) were taking three or more medications. Overall Health Status One in 6 adults (18.0%) reported experiencing fair or poor overall health, while 82.0% reported experiencing good, very good, or excellent overall health at Stage 1. The total proportion reporting fair or poor overall health decreased to 15.2% at Stage 2, although 7.0% of those reporting good to excellent health at Stage 1 were experiencing fair or poor health at Stage 2. Quality of Life Between Stage 1 and Stage 2, quality of life, as measured by the SF-36, significantly improved for the dimensions of Vitality (mean score increased from 60.5 at Stage 1 to 63.1 at Stage 2), Social Functioning (84.8 at Stage 1 to 88.5 at Stage 2), and Mental Health (74.8 at Stage 1 to 77.6 at Stage 2). 12
Chronic Conditions 13
Asthma The following overview presents the prevalence and incidence of asthma among the participants of the North West Adelaide Health Study. Stage 1 (baseline examination) was conducted between 2000 and 2003, and Stage 2 (second examination) was conducted from 2004 to 2006. Measurement and definition of asthma Asthma was determined by spirometry based on three pre- and three post-salbutamol measurements. People with current asthma were defined as those who reported having been told by a doctor that they have asthma, or those who had at least a 12% increase in FEV 1 (forced expiratory volume in one second) from pre-ventolin to post-ventolin if their absolute difference in FEV 1 was greater than 200ml 1 or they had an absolute change in FEV 1 of greater than or equal to 400ml. Incidence of asthma The annual incidence of asthma between Stage 1 and Stage 2 was 24.6 cases per 1000 in the adult population. Prevalence of asthma Stage 1 & Stage 2 The prevalence of asthma for both Stage 1 and Stage 2 is shown in Table 1. In Stage 1, 12.5% (95% CI 11.5-13.6) and in Stage 2, 16.2% (95% CI 15.0-17.5) of study participants had asthma. Table 1: Prevalence of asthma Stage 1 Stage 2 n % n % No asthma 3549 87.5 2685 83.8 Asthma 509 12.5 520 16.2 Total 4058* 100.0 3205* 100.0 * Note: (Stage 1) 2 participants and (Stage 2) 1 participant had insufficient FEV 1 results or did not state they had been told that they had asthma and were excluded. Transition to and from asthma Overall, 7.6% (95% 6.7-8.6) of respondents went from having no asthma in Stage 1 to asthma in Stage 2 and 8.6% (95% 7.7-9.7) had asthma in Stage 1 and Stage 2 (Table 2). Table 2: The transition to and from asthma Stage 1 Stage 2 n % No asthma No asthma 2601 81.1 No asthma Asthma 243 7.6 Asthma Asthma 277 8.6 Asthma No asthma 84 2.6 Total 3205 100.0 The high incidence of asthma may be due to the variability of asthma as a disease, and the potential of measuring undiagnosed, but present, asthma in Stage 1. Some respondents that went from asthma to no asthma, or from no asthma to asthma, typically just qualified as having asthma, and could be added to the no asthma/no asthma group. 14
COPD The following overview presents the prevalence and incidence of chronic obstructive pulmonary disease (COPD), including bronchitis and emphysema, among the participants of the North West Adelaide Health Study. Stage 1 (baseline examination) was conducted between 2000 and 2003, and Stage 2 (second examination) was conducted from 2004 to 2006. Measurement and definition of COPD COPD was measured by spirometery according to the American Thoracic Society standards. People with COPD, based on the GOLD (Global Initiative for Obstructive Lung Disease) definition, were defined as those with a post bronchodilator FEV 1 :FVC ratio of less than 70% 2. Incidence of COPD The annual incidence of COPD between Stage 1 and Stage 2 was 6.1 incident cases per 1000 in the adult population. Prevalence of COPD Stage 1 & Stage 2 The prevalence of undiagnosed COPD in Stage 2 (COPD defined by spirometry tests without self-reported doctor diagnosed COPD) was 3.4% (95% CI 2.8-4.1). The prevalence of diagnosed COPD (COPD defined by spirometry tests and self-reported doctor diagnosed COPD) was 1.4% (95% CI 1.0-1.9). The overall prevalence of COPD (diagnosed and undiagnosed) for both Stage 1 and Stage 2 is shown in Table 1. Overall, in Stage 1 3.9% (95% CI 3.3-4.5) and in Stage 2 4.8% (95% CI 4.1-5.6) of study participants had COPD. Table 1: Prevalence of COPD Stage 1 Stage 2 n % n % No COPD 3861 96.1 3000 95.2 COPD 156 3.9 150 4.8 Total 4017* 100.0 3149* 100.0 * Note: (Stage 1) 43 participants and (Stage 2) 57 participants had inufficient FEV1 or FVC results and were excluded Transition to and from COPD Overall, 1.9% (95% CI 1.5-2.5) of respondents went from having no COPD in Stage 1 to COPD in Stage 2 and 2.8% (95% CI 2.3-3.4) had COPD in Stage 1 and Stage 2 (Table 2). Table 2: Transition to and from COPD Stage 1 Stage 2 n % No COPD No COPD 2960 94.6 No COPD COPD 60 1.9 COPD COPD 88 2.8 COPD No COPD 20 0.6 Total 3128 100.0 Some respondents that went from COPD to no COPD, or from no COPD to COPD, typically just qualified as having COPD, and could be added to the no COPD/no COPD group. 15
CVD The following overview presents the prevalence and incidence of cardiovascular disease (CVD) among the participants of the North West Adelaide Health Study. Stage 1 (baseline examination) of the study was conducted between 2000 and 2003, and Stage 2 (second examination) was conducted from 2004 to 2006. Measurement and definition of cardiovascular disease The prevalence of CVD was calculated using data obtained from the telephone interview. Participants were asked if had been told by a doctor that they had ever had a heart attack, a stroke or angina. In Stage 2 participants were also asked if they had ever had a transient ischaemic attack (TIA), which is also known as a mini stroke. Incidence of cardiovascular disease The annual incidence of cardiovascular disease between Stage 1 and Stage 2 was 5.6 incident cases per 1000 in the adult population. Prevalence of cardiovascular disease Stage 1 & Stage 2 The prevalence of self-reported cardiovascular disease for both Stage 1 and Stage 2 is shown in Table 1. For the purposes of comparison, the prevalence of TIA is not included in the prevalence of CVD. Overall, in Stage 1 6.2% (95% CI 5.5-6.9) and in Stage 2 5.7% (95% CI 5.0-6.5) of study participants had cardiovascular disease. The prevalence of cardiovascular disease including TIA in Stage 2 was 6.7% (95% CI 5.9-7.6). Table 1: Prevalence of cardiovascular disease (not including TIA) (Self Report) Stage 1 Stage 2 n % n % No CVD 3806 93.8 3296 94.3 CVD 250 6.2 198 5.7 Total 4055* 100.0 3494* 100.0 * Note: (Stage 1) 5 participants and (Stage 2) 8 participants did not know or refused to respond and were excluded from the analysis Transition to and from cardiovascular disease Overall, 2.2% (95% CI 1.8-2.7) of participants went from not having CVD in Stage 1 to having CVD in Stage 2 (Table 2). Table 2: Transition to and from cardiovascular disease (not including TIA) Stage 1 Stage 2 n % No CVD No CVD 3239 92.8 No CVD CVD 77 2.2 CVD CVD 121 3.5 CVD No CVD 54 1.5 Total 3491 100.0 The explanation for the group who went from reporting a CVD event to not reporting one is unknown. This measure was not clinically assessed, and the nature of self-report information relies on errors, corrections, memory lapses, and increased knowledge. This difference could also be explained by question wording differences at Stage 1 and Stage 2. 16
Diabetes The following overview presents the prevalence and incidence of diabetes among the participants of the North West Adelaide Health Study. Stage 1 (baseline examination) was conducted between 2000 and 2003, and Stage 2 (second examination) was conducted from 2004 to 2006. Measurement and definition of diabetes People with diabetes were defined as those who had a fasting plasma glucose (FPG) level of at least 7.0mmol/L or those who self-reported having been told by a doctor that they have diabetes. Incidence of diabetes The annual incidence of diabetes between Stage 1 and Stage 2 was 6.8 incident cases per 1000 in the adult population. Prevalence of diabetes Stage 1 & Stage 2 The prevalence of diabetes is shown in Table 1. Overall in Stage 1, 6.6% (95% CI 5.8-7.4) and in Stage 2, 7.2% (95% CI 6.3-8.1) of study participants had diabetes. Table 1: Prevalence of diabetes Stage 1 Stage 2 n % n % No diabetes 3793 93.4 2949 92.8 Diabetes 267 6.6 228 7.2 Total 4060 100.0 3178* 100.0 * Note: (Stage 2) 28 participants did not provide blood and were excluded Transition to and from diabetes Overall, 2.1% (95% CI 1.7-2.7) went from not having diabetes in Stage 1 to having diabetes in Stage 2. There was also a proportion of respondents who reported that they had diabetes in Stage 1 but did not have diabetes in Stage 2 (0.8%; 95% CI 0.5-1.1). The results are summarised in Table 2. Table 2: The transition to and from diabetes Stage 1 Stage 2 n % No diabetes No diabetes 2925 92.1 No diabetes Diabetes 68 2.1 Diabetes Diabetes 160 5.0 Diabetes No diabetes 24 0.8 Total 3178 100.0 Some respondents that went from diabetes to no diabetes, or from no diabetes to diabetes, typically just qualified as having diabetes, and could be added to the no diabetes/no diabetes group. 17
Mental Health Condition The following overview presents the prevalence and incidence of current mental health conditions among the participants of the North West Adelaide Health Study. Stage 1 (baseline examination) was conducted between 2000 and 2003, and Stage 2 (second examination) was conducted from 2004 to 2006. Measurement and definition of a current mental health condition The prevalence of having a current mental health condition was calculated using data obtained from the self report telephone interview. Participants were asked if had been told by a doctor in the last twelve months that they had any of the following conditions: anxiety, depression, a stress related problem, or any other mental health problem. Incidence of a current mental health condition The annual incidence of developing a current mental health between Stage 1 and Stage 2 was 22.9 per 1000 in the adult population. Prevalence of a current mental health condition Stage 1 & Stage 2 The prevalence of self-reported current mental health conditions for both Stage 1 and Stage 2 is shown in Table 1. Overall, in Stage 1 13.6% (95% CI 12.6-14.7) and in Stage 2 16.1% (95% CI 14.9-17.4) of study participants had a current mental health condition. Table 1: Prevalence of a current mental health condition (Self Report) Stage 1 Stage 2 n % n % No mental health condition 3487 86.4 2929 83.9 A current mental health condition 54 13.6 563 16.1 Total 4035* 100.0 3492* 100.0 * Note: (Stage 1) 25 participants and (Stage 2) 10 participants did not state or did not know if they had a current mental health condition and were excluded Transition to and from a current mental health condition Overall, 9.3% (95% CI 8.4-10.3) of respondents did not have a current mental health condition in Stage 1 and had a current mental health condition in Stage 2. There was also 6.8% (95% CI 6.0-7.7) of respondents who had a current mental health condition in Stage 1 and Stage 2 (Table 2). Table 2: Transition to and from a current mental health condition Stage 1 Stage 2 n % No mental health condition No mental health condition 2688 77.4 No mental health condition Mental health condition 322 9.3 Mental health condition Mental health condition 237 6.8 Mental health condition No mental health condition 224 6.5 Total 3472 100.0 Mental health conditions can be transient, and can resolve over time. This explains the proportion of participants who reported having a mental health condition at Stage 1 and then reported not having a mental health condition at Stage 2. 18
Depression The following overview presents the prevalence of depression, as measured by the Centre for Epidemiologic Studies Depression Scale (CES-D), among the participants of the North West Adelaide Health Study. Prevalence of depression was only included at Stage 2 of the study (conducted from 2004 to 2006). Measurement and definition of depression The prevalence of depression was calculated using data obtained from the self report telephone interview using the Centre for Epidemiologic Studies Depression Scale (CES-D) 3. Participants were asked 20 items which were scored together to identify depression in this population. A score of 16 or higher classifies persons as having depressive symptoms. Prevalence of depression Stage 2 The prevalence of depression, as measured by the CES-D, is shown in Table 1. In Stage 2, 12.4% (95% CI 11.3-13.5) of study participants had depression. Table 1: Prevalence of a depression (CES-D) Stage 2 n % No depression 3057 87.6 Depression 431 12.4 Total 3488 100.0 Note: (Stage 2) 14 participants did not provide responses to questions and were excluded Classification of depression The depression status of participants, assessing mild or moderate according to the self report questionnaire at Stage 2, is shown in Table 2. When cutoffs for the subtypes of depression are used, 8.5% (95% CI 7.6-9.5) of participants experienced mild depression and 3.9% (95% CI 3.3-4.6) experienced moderate to severe depression 4. Table 2: Depression Classification in Stage 2 (CES-D) Stage 2 n % No depression (CES-D < 16) 3057 87.6 Mild depression (CES-D >16 and < 26) 296 8.5 Moderate to severe depression (CES-D > 26) 135 3.9 Total 3488 100.0 Note: (Stage 2) 14 participants did not respond to the questions and were excluded 19
Psychological Wellbeing The following overview presents the prevalence of psychological wellbeing among the participants of the North West Adelaide Health Study. Questions regarding psychological wellbeing, as measured by the General Health Questionnaire 12 (GHQ-12), were included in Stage 2 of the study (conducted from 2004 to 2006). Measurement and definition of psychological wellbeing The prevalence of psychological wellbeing categories were calculated using data obtained from the self report questionnaire using Goldberg's General Health Questionnaire (GHQ-12) 5. The GHQ-12, a subset of the GHQ-28, is a screening questionnaire for detecting current, independently verifiable forms of psychiatric illness, including depression, anxiety, social impairment and hypochondriasis. It does not make a clinical diagnosis. It is the most widely applied self completion measure of psychiatric disturbance in the UK and has numerous worldwide applications. Participants were asked 12 questions which were scored together to gauge psychological wellbeing in this population. A score of 0 or 1 classifies persons as having "low or no disturbance", 2 to 3 as having "mild or moderate disturbance" and 4 or greater as having "high or severe disturbance". Prevalence of psychological wellbeing Stage 2 The prevalence of different levels of psychological wellbeing according to the GHQ-12 self report questionnaire for Stage 2 is shown in Table 1. In Stage 2, 11.1% (95% CI 10.0-12.2) of study participants had a mild or moderate disturbance, and 13.5% (95% CI 12.4-14.7) had a high or severe disturbance. Table 1: Prevalence of psychological wellbeing GHQ-12 (Self Report) Stage 2 n % Low or no disturbance 2454 75.4 Mild or moderate disturbance 360 11.1 High or severe disturbance 440 13.5 Total 3254 100.0 * Note: (Stage 2) 6 participants had four or more GHQ variables missing and were excluded Psychological wellbeing and current mental health condition Stage 2 The levels of psychological wellbeing were assessed in the participants who had also self reported a current mental health condition, that is anxiety, depression or a stress related problem. Of participants with a current mental health condition, 37.5% (95% CI 33.3-41.8) reported a high or severe disturbance (Table 2). Table 2: Prevalence of psychological wellbeing in those with a current mental health condition n % Low or no disturbance 231 46.6 Mild or moderate disturbance 79 15.9 High or severe disturbance 186 37.5 Overall 496 100.0 20
Renal Disease The following overview presents the prevalence of chronic kidney disease (CKD) among the participants of the North West Adelaide Health Study. CKD is defined as Glomerular Filtration Rate (GFR) less than 60 ml/minute/1.73m 2 or kidney damage for three months or more 6. The prevalence of CKD was determined by microalbuminuria and estimated GFR (egfr). CKD was only examined at Stage 2 of the study (conducted from 2004 to 2006). Measurement of chronic kidney disease Microalbuminuria and GFR were determined from blood and urine analysis conducted as part of the clinic assessment. From the samples provided by participants, urine albumin and creatinine were determined and used to calculate the albumin to creatinine ratio. Microalbuminuria was defined as >=2.5 g/mol for males and >=3.5 g/mol for females, with macroalbuminuria (overt albuminuria) >=25 g/mol for males and >= 34 g/mol for females. The serum creatinine was also determined and used to estimate the glomerular filtration rate (egfr). The formula used was derived from the Modification of Diet in Renal Disease (MDRD) Study 7 and is as follows: GFR=186.3 ((serum creatinine/88.4) ^ (-1.154)) * age ^ (-0.203). This equation is for males; for females the GFR value is multiplied by 0.742. Prevalence of chronic kidney disease defined by microalbuminuria Stage 2 The prevalence of microalbuminuria is shown in Table 1. Overall, in Stage 2, 5.5% (95% CI 4.7-6.4) of study participants had microalbuminuria (including macroalbuminuria). Table 1: Prevalence of CKD as defined by microalbuminuria Stage 2 n % No microalbuminuria 2861 94.5 Microalbuminuria 150 5.0 Macroalbuminuria 16 0.5 Total 3027 100.0 Note: (Stage 2) 179 participants did not provide a specimen and were excluded. Prevalence of chronic kidney disease defined by egfr Stage 2 The prevalence of chronic kidney disease defined by egfr is shown in Table 2. Overall, 11.4% (95% CI 10.4-12.6) of participants had Stage 3, 4 or 5 CKD using the MDRD equation to determine the egfr, with 0.4% (95% CI 0.2-0.6) having Stage 4 CKD and 0.1% (95% CI 0.0-0.3) with Stage 5 CKD. Table 2: Prevalence of chronic kidney disease as defined by egfr (ml/minute/1.73m 2 ) Stage 2 n % egfr >= 60 (No kidney damage, Stage 1, Stage 2 CKD) 2816 88.6 egfr >= 30 and < 60 (Stage 3 CKD) 348 11.0 egfr >= 15 and < 30 (Stage 4 CKD) 12 0.4 egfr < 15 (Stage 5 CKD) 3 0.1 Total 3179 100.0 Note: (Stage 2) 27 participants did not provide blood and were excluded. 21
Musculoskeletal Conditions 23
Arthritis The following overview presents the prevalence of arthritis among the participants of the North West Adelaide Health Study. This aspect of the study was included at Stage 2 (conducted from 2004 to 2006). Measurement of arthritis The prevalence of arthritis was determined using data obtained from the self report telephone interview at Stage 2 of the study. Participants were asked if they had osteoarthritis, rheumatoid arthritis, another form of arthritis, or if they did not know the type of arthritis they had. Prevalence of arthritis Stage 2 The prevalence of all forms of arthritis is shown in Table 1. Overall, in Stage 2, 21.4% (95% CI 20.1-22.8) of study participants had arthritis. Table 1: Prevalence of arthritis Stage 2 n % No arthritis 2734 78.6 Arthritis 744 21.4 Total 3478 100.0 Note: (Stage 2) 24 participants did not provide a response to questions and were excluded. Prevalence of types of arthritis The prevalence of each type of arthritis is shown in Table 2. Overall, 7.5% (95% CI 6.6-8.4) of participants reported that they had osteoarthritis and 2.9% (95% CI 2.4-3.5) of participants reported that they had rheumatoid arthritis. In addition, 10.8% (95% CI 9.8-11.8) of respondents did not know the type of arthritis that they had. Other types of arthritis included: Ankylosing spondylitis, Fibromyalgia, Gout, Keinbock's disease, Systemic lupus erythematosus, Polyarthritis, Pseudo gout, Psoriatic arthritis, Reactive arthritis (Reiters syndrome), Seronegative arthritis and Sjögrens syndrome. Table 2: Prevalence of types of arthritis* Stage 2 n % Osteoarthritis 261 7.5 Rheumatoid arthritis 101 2.9 Other type of arthritis 18 0.5 Don t know what type 377 10.8 *Multiple responses possible 24
Back Pain The following overview presents the prevalence of back pain among the participants of the North West Adelaide Health Study. This aspect of the study was included at Stage 2 (conducted from 2004 to 2006). Measurement of back pain The prevalence of back pain was determined using self report data obtained from the telephone interview. Participants were asked if they had ever had pain or aching in their low back either at rest or when moving on most days for at least a month. Participants were also asked if they ever had back stiffness when first getting out of bed and whether the stiffness had lasted at least 15 minutes. Prevalence of back pain Stage 2 The prevalence of back pain either at rest or when moving is shown in Table 1. Overall, in Stage 2, 30.3% (95% CI 28.8-31.9) of study participants had low back pain either at rest or when moving. Table 1: Prevalence of back pain either at rest or when moving Stage 2 n % No back pain 2434 69.7 Back pain 1060 30.3 Total 3494 100.0 Note: (Stage 2) 8 participants did not provide a response to questions and were excluded Prevalence of back stiffness Stage 2 The prevalence of back stiffness either at rest or when moving is shown in Table 2. Overall, 23.2% (95% CI 21.8-24.6) of study participants reported ever having back stiffness. Of the participants who had back stiffness, 59.9% (95% CI 56.5-63.2) had stiffness which lasted at least 15 minutes. Table 2: Prevalence of back stiffness Stage 2 n % No back stiffness 2683 76.8 Back stiffness 808 23.2 Total 3491 100.0 Note: (Stage 2) 11 participants did not provide a response to questions and were excluded Prevalence of back pain and/or stiffness Stage 2 Overall, the prevalence of back pain and/or stiffness in Stage 2 was 34.9% (95% CI 33.3-36.5). Table 2: Prevalence of back pain and/or stiffness n % Pain and stiffness 649 18.6 Back pain only 411 11.8 Back stiffness only 160 4.6 No back pain or stiffness 2273 65.1 Total 3493 100.0 Note: (Stage 2) 9 participants did not provide a response to one or both questions and were excluded 25
Foot Pain The following overview presents the prevalence of foot pain among the participants of the North West Adelaide Health Study. This aspect of the study was included at Stage 2 (conducted from 2004 to 2006). Measurement of foot pain Information relating to foot pain was obtained from the telephone interview and during the clinic assessment. Respondents were asked over the telephone whether they have pain, aching or stiffness, on most days, in either of their feet, the severity and the length of time they had pain. Participants who undertook the clinic assessment were also asked whether they have pain, aching or stiffness in either of their feet on most days, and asked to indicate on a foot diagram where the pain, aching or stiffness was located. Prevalence of foot pain Stage 2 (self report) The self reported prevalence of foot pain as determined the telephone interview data is shown in Table 1. In Stage 2, 15.0% (95% CI 13.8-16.2) of study participants reported that they had foot pain in one or both feet. Table 1: Prevalence of self reported foot pain (CATI assessment) Stage 2 n % No 2971 85.0 Yes left foot 100 2.9 Yes right foot 104 3.0 Yes both feet 319 9.1 Total 3494 100.0 Note: (Stage 2) 8 participants did not know, 1 participant not applicable (amputee) and were excluded Severity of foot pain Participants were asked about the severity of the pain aching or stiffness in each of their feet. Overall, respondents most commonly rated their foot pain as mild in either the left or the right foot (46.0% and 48.4% respectively) (Table 2). Table 2: Severity of foot pain Left Right n % n % Mild 193 46.0 205 48.4 Moderate 168 40.0 142 33.5 Severe 54 13.0 72 17.0 Don t know 4 1.0 4 1.0 Total 419 100.0 423 100.0 26
Hip Pain The following overview presents the prevalence of hip pain among the participants of the North West Adelaide Health Study. This aspect of the study was included in Stage 2 of the study (conducted from 2004 to 2006). Measurement of hip pain Information relating to hip pain was obtained from the self report telephone interview. Respondents were asked whether they have had a hip injury, a hip joint replacement, hip pain at rest or when moving on most days of the week for at least a month, hip stiffness when getting out of bed on most days for at least a month and whether the stiffness last for at least 15 minutes. Prevalence of hip pain and stiffness Respondents who had not had both hips replaced were asked whether they pain, aching or stiffness in their knees either at rest or moving, on most days for at least a month. Overall 9.2% (95% CI 8.3-10.3) reported that they had had pain in their hip (Table 3). Respondents were also asked if they had ever had stiffness in their hip joints or muscles when first getting out of bed on most days for at least a month. Overall 7.7% (95% CI 6.9-8.7) reported that they had hip stiffness. Of those with hip stiffness, 63.9% (95% CI 58.0-69.4) reported that the stiffness lasted at least 15 minutes. Finally, respondents were asked if their hip pain or stiffness was only as a result of a sprain, strain, fracture or dislocation. Overall, 15.7% (95% CI 12.4-19.7) of respondents with hip pain or stiffness reported that this was the case. Table 1: Prevalence of hip pain and hip stiffness Hip pain Hip stiffness n % n % No 3160 90.8 3211 92.3 Yes 322 9.2 269 7.7 Total 3482 100.0 3480 100.0 Note: (Stage 2) 9 and 12 participants respectively did not provide a response and were excluded 27
Knee Pain The following overview presents the prevalence of knee pain among the participants of the North West Adelaide Health Study. This aspect of the study was included in Stage 2 of the study (conducted from 2004 to 2006). Measurement of knee pain Information relating to knee pain and arthritis was obtained through the self report telephone interview. Respondents were asked whether they have knee pain and whether they have doctor diagnosed knee arthritis. Respondents who reported knee pain or stiffness either at rest or when moving, on most days for at least a month, were also asked the Western Ontario McMaster University (WOMAC ) Osteoarthritis Index, which is a series of questions examining knee pain stiffness and functioning 8. Prevalence of knee pain Respondents who had not had both knees replaced were asked whether they experienced pain, aching or stiffness in their knees either at rest or moving, on most days for at least a month. Overall, 16.0% (95% CI 14.8-17.3) reported that they had pain in their knees (Table 3). Of the respondents who had knee pain, 43.9% (95% CI 39.9-48.1) reported that the pain was due to a sprain, strain, cartilage/meniscus damage, fracture, or dislocation. Table 1: Prevalence of knee pain Stage 2 n % Yes 554 16.0 No 2903 84.0 Total 3458 100.0 Note: (Stage 2) 27 participants did not know and were excluded. 28
Osteoporosis The following overview presents the prevalence of osteoporosis among the participants of the North West Adelaide Health Study. This aspect of the study was included in Stage 2 of the study (conducted from 2004 to 2006). Measurement of osteoporosis The prevalence of osteoporosis was determined using data obtained from the self report telephone interview, where participants were asked if they had ever been told by a doctor that they have osteoporosis. Participants aged 50 years and over were also offered the opportunity to have a Dual Energy X-ray Absorptiometry (DEXA) scan. Osteoporosis exists when a bone mineral density (BMD) value is more than 2.5 standard deviations below the average BMD of young adult, Caucasian women. Osteopenia is present when the BMD value is between 1 and 2.5 standard deviations below the mean BMD of young adult, Caucasian women. Prevalence of osteoporosis Stage 2 (self report) The self reported prevalence of osteoporosis is shown in Table 1. Overall, in Stage 2, 3.8% (95% CI 3.2-4.5) of study participants reported that they osteoporosis 9. Table 1: Prevalence of self reported osteoporosis Stage 2 n % No osteoporosis 3361 96.2 Osteoporosis 133 3.8 Total 3494 100.0 Note: (Stage 2) 8 participants did not provide a response to questions and were excluded Prevalence of osteoporosis Stage 2 (clinic measurement) The prevalence of osteoporosis among participants aged 50 years and over who had a DEXA scan is shown in Table 2. Overall, 15.0% (95% CI 13.0-17.3) of participants were classified as osteopenic and 3.6% (95% CI 2.6-4.9) were classified as osteoporotic. Among respondents who self reported that they did not have osteoporosis, 12.6% (95% CI 10.6-14.8) were classified as osteopenic by DEXA scan and 2.9% (95% CI 2.0-4.1) were classified as osteoporotic. Table 2: Prevalence of osteoporosis (clinic assessment) Stage 2 n % No osteoporosis 868 81.4 Osteopenia 160 15.0 Osteoporosis 38 3.6 Total 1067 100.0 Note: 282 Stage 2 participants aged 50 years and over did not have a DEXA scan and were excluded. In addition, ten participants aged 42 to 49 had a DEXA scan. 29
Shoulder Pain The following is an overview of shoulder pain among the participants of the North West Adelaide Health Study. This aspect of the study was included in Stage 2 of the study (conducted from 2004 to 2006). Measurement of shoulder pain Information relating to shoulder pain was obtained in the self report telephone interview. Respondents were asked whether they have had shoulder pain or stiffness in the past month. Respondents who reported shoulder pain or stiffness on most days for at least a month were also asked the Shoulder Pain and Disability Index (SPADI), which is a series of questions examining pain and stiffness and used as a clinical assessment tool of pain and disability associated with a painful shoulder 10. Shoulder range of movement was also measured as part of the clinic assessment. Prevalence of shoulder pain Stage 2 (self report) The self reported prevalence of shoulder pain (pain or aching in shoulder either at rest or when moving, on most days for at least a month) is shown in Table 1. In Stage 2, 20.9% (95% CI 19.6-22.2) of study participants reported that they had shoulder pain most days for at least a month. Table 1: Prevalence of self reported shoulder pain Stage 2 n % No shoulder pain 2760 79.1 Shoulder pain 728 20.9 Total 3488 100.0 Note: (Stage 2) 14 participants did not know and were excluded Prevalence of shoulder stiffness Stage 2 Participants were asked if they had had stiffness in their shoulder when first getting out of bed in the morning, on most days for at least a month. Overall, 12.4% (95% CI 11.3-13.5) of respondents had shoulder stiffness (Table 2). Of those reporting shoulder stiffness, 77.5% (95% CI 73.4-81.2) stated that the stiffness lasted at least 15 minutes. Table 2: Prevalence of self reported shoulder stiffness Stage 2 n % No shoulder stiffness 3062 87.6 Shoulder stiffness 432 12.4 Total 3494 100.0 Note: (Stage 2) 8 participants did not provide a response and were excluded 30
31 Risk Factors
Alcohol The following overview presents the prevalence and incidence of alcohol consumption among the participants of the North West Adelaide Health Study. Stage 1 (baseline examination) of the study was conducted between 2000 and 2003, and Stage 2 (second examination) was conducted from 2004 to 2006. Measurement and definition of alcohol consumption Alcohol consumption prevalence was calculated using data obtained from the self report questionnaire. Participants were asked how often they drank alcohol and, if they drank, on a day when they drank alcohol, how many drinks they usually had. The participants were then classified according to their level of risk, as non-drinkers or no risk, low alcohol risk, and intermediate to very high alcohol risk 11. Incidence of high risk alcohol consumption The annual incidence of becoming an intermediate to high risk drinker between Stage 1 and Stage 2 was 9.6 incident cases per 1000 in the adult population. The annual incidence of becoming a no or low risk alcohol drinker between Stage 1 and Stage 2 was 11.2 incident cases per 1000 in the adult population. Prevalence of alcohol consumption Stage 1 & Stage 2 The prevalence of different categories of alcohol consumption for Stage 1 and Stage 2 is shown in Table 1. In Stage 1, 6.1% (95% CI 5.4-6.8) and in Stage 2, 5.7% (95% CI 4.9-6.6) of study participants were intermediate to very high risk alcohol drinkers. Additionally in Stage 1, 53.4% (95% CI 51.9-54.9) and in Stage 2, 50.8% (95% CI 49.0-52.5) of study participants were non drinkers or at no risk. Table 1: Prevalence of alcohol consumption Stage 1 Stage 2 n % n % Non-drinker, no risk 2148 53.4 1592 50.8 Low alcohol risk 1630 40.5 1364 43.5 Intermediate to Very High alcohol risk 244 6.1 178 5.7 Total 4023* 100.0 3135* 100.0 * Note: (Stage 1) 37 participants and (Stage 2) 125 participants did not provide responses and were excluded Transition to and from various levels of alcohol consumption Overall, 3.4% (95% CI 2.8-4.1) of participants went from being a non or low risk drinker in Stage 1 to an intermediate or high risk drinker in Stage 2 (Table 2). Table 2: Transition to and from various levels of alcohol consumption Stage 1 Stage 2 n % Non/ No/ Low Risk Non/ No/ Low Risk 2822 90.5 Non/ No/ Low Risk Intermediate/ Very High Risk 106 3.4 Intermediate/ Very High Risk Intermediate/ Very High Risk 72 2.3 Intermediate/ Very High Risk Non/ No/ Low Risk 120 3.8 Total 3120 100.0 32