R. G. Weaver 1, B. R. Hemmelgarn 1,2, D. M. Rabi 1,2, P. M. Sargious 1, A. L. Edwards 1, B. J. Manns 1,2, M. Tonelli 3 and M. T. James 1,2.

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1 Short Report: Educational and Psychological Issues Association between participation in a brief diabetes education programme and glycaemic control in adults with newly diagnosed diabetes R. G. Weaver 1, B. R. Hemmelgarn 1,2, D. M. Rabi 1,2, P. M. Sargious 1, A. L. Edwards 1, B. J. Manns 1,2, M. Tonelli 3 and M. T. James 1,2 1 Department of Medicine, University of Calgary, 2 Department of Community Health Sciences, University of Calgary, Calgary and 3 Department of Medicine, University of Alberta, Edmonton, AB, Canada Accepted 30 May 2014 DOI: /dme Abstract Aims To determine the association between participation in a brief introductory didactic diabetes education programme and change in HbA 1c among individuals with newly diagnosed diabetes. Methods We identified a population-based cohort of adults newly diagnosed with diabetes between October 2005 and June 2008 in Calgary, Canada, and conducted a retrospective cohort study by linking administrative and laboratory data with programme attendance data. We matched individuals who attended the programme within the first 6 months after diagnosis with those who did not attend, based on their propensity scores. We measured the change in HbA 1c between time of diagnosis and 6 18 months later to determine the association between programme participation and change in HbA 1c. Results HbA 1c was measured at baseline and follow-up for 7793 individuals, including 803 programme participants. After propensity score matching, programme participation was associated with a significantly greater adjusted mean reduction in HbA 1c between baseline and follow-up of 3.3 mmol/mol (95% CI ) or 0.30% (95% CI ). There was a significant interaction between baseline HbA 1c and programme participation the difference in adjusted mean reduction in HbA 1c associated with programme participation ranged from 2.7 mmol/mol (0.25%) at baseline HbA 1c of 53 mmol/mol (7%) to 6.2 mmol/mol (0.56%) at baseline HbA 1c of 97 mmol/mol (11%). Conclusion Despite its brevity, participation in a diabetes education programme was associated with an additional reduction in HbA 1c in newly diagnosed people that was comparable with that reported in trials of programmes targeted at those with prevalent diabetes. Diabet. Med. 31, (2014) Introduction Clinical practice guidelines for Type 2 diabetes endorse the use of patient education to promote self-management, which includes both didactic and participatory components [1]. Systematic reviews of randomized controlled trials in Type 2 diabetes have consistently reported that both didactic patient education and non-didactic self-management approaches are effective at lowering HbA 1c [2 7], with effect size estimates ranging from a reduction of 1.6 mmol/mol to 3.5 mmol/mol (0.15% to 0.32%) [3,7,8] for didactic patient education, and from 2.3 mmol/mol to 8.9 mmol/mol (0.21% to 0.81%) [2, 5 7] for self-management. Little is known, however, about the effectiveness of patient education on glycaemic control in Correspondence to: Matthew T. James. mjames@ucalgary.ca people with newly diagnosed diabetes, particularly in real-- world settings where programmes are scaled up for broader delivery. We sought to determine the association between participation in [9], a brief, introductory diabetes education programme, and glycaemic control among newly diagnosed individuals, and examined whether the association varied with baseline HbA 1c. Subjects and methods Cohort formation We performed a retrospective cohort study using administrative and laboratory data [10] linked with attendance data for. The study population consisted of 1610 Diabetic Medicine ª 2014 UK

2 Research article DIABETICMedicine What s new? This study investigated the association between participation in a brief diabetes education programme and change in glycaemic control in people with newly diagnosed diabetes. Few studies have reported on the effect of such interventions in people with newly diagnosed diabetes, particularly in real-world settings. With our large sample size, we were able to estimate the change in glycaemic control for different levels of baseline HbA 1c more accurately than previous studies. These findings provide important evidence supporting diabetes education for newly diagnosed individuals and, given that it is relatively low cost to implement, has implications for programme delivery. adults aged 18 years or older residing in the Calgary Zone of Alberta Health Services, Canada (population 1.3 million), who were diagnosed with diabetes between 1 October 2005 and 30 June diagnosis was defined using a validated algorithm {at least two physician claims for diabetes within 2 years [International Classification of Diseases (ICD)-9-CM code 250], or one hospitalization for diabetes (ICD-10-CA codes E10 E14)} [11]. The date of diabetes diagnosis (the index date) was the date of hospitalization, or the earlier of the two physician claims, whichever occurred first. Measurement of study variables The exposure was attendance at in the first 6 months following diagnosis. is a free, publicly funded introductory diabetes education programme, accessed through physician or self-referral, and mainly targets people with newly diagnosed Type 2 diabetes. The programme consists of 5 7 h of instruction over 1 or 2 days, including sections on diabetes management, diet, exercise, managing stress, glucose self-monitoring and medication [9]. We considered that one session constituted attendance. is taught by a diabetes nurse educator and a dietician, is offered over 100 times per year at various locations in and around Calgary, and over 1000 individuals attend annually. Some programmes are offered in the language of ethnic groups at high risk for diabetes, such as Cantonese and Punjabi. The primary study outcome was change in HbA 1c from baseline to follow-up. Baseline HbA 1c was defined as the HbA 1c measurement closest to the index date in the period from 90 days prior to 30 days after diagnosis. Follow-up HbA 1c was defined as the mean measurement between 6 and 18 months following the index date. We obtained covariates, listed in Table 1, from the administrative data sources and assessed them at the index date. We defined the 17 co-morbidities in the Charlson Index and the presence of an affective disorder using validated algorithms [12 14]. Statistical analysis We used propensity score matching to balance potential confounders between treatment groups [15]. We created a logistic regression model for participation in in the first 6 months after diagnosis and calculated individuals propensity scores as the probability of attending the programme, given their baseline covariates. We then used the propensity scores to create a 1:1 matched sample, matching on the logit of the propensity score. We matched within 10 strata defined by deciles of baseline HbA 1c,to examine the interaction between baseline HbA 1c and participation. We used nearest neighbour greedy matching without replacement, within a caliper of 0.2 SD of the logit of the propensity score [16]. After confirming balance between the two groups, we determined the association between programme participation and change in HbA 1c by using generalized estimating equations, with robust standard errors to address clustering within matched pairs. These models were adjusted for continuous baseline HbA 1c, and age, and mean time to follow-up HbA 1c measurement (to adjust for difference in timing of the follow-up measurements). All analyses were conducted using Stata MP for Windows version 11.2 (StataCorp., College Station, TX, USA). The study was approved by the institutional review board of the University of Calgary. Results Cohort description We identified adults aged 18 years and older residing in the Calgary Zone with diabetes diagnosed between 1 October 2005 and 30 June 2008, of whom 7793 (47.5%) had HbA 1c measured at both baseline and follow-up. There were 1233 individuals (7.5%) who attended within 6 months following diabetes diagnosis, including 803 with HbA 1c measured at baseline and follow-up. Cohort characteristics are described in Table 1. For the propensity matching, the logistic regression model to predict participation included age and baseline HbA 1c as continuous variables, with quadratic terms to address non-linearity. We excluded 41 non-participants with a metastatic tumour and four with HIV/AIDS as there were no participants with these conditions, leaving a cohort of Following propensity score matching, 802 of the 803 Diabetic Medicine ª 2014 UK 1611

3 education and glycaemic control R. G. Weaver et al. Table 1 Characteristics of adults with baseline and follow up HbA 1c measurements who did and did not attend in the first 6 months after diabetes diagnosis, in entire cohort and after propensity score matching Entire cohort After propensity score matching Characteristic Did not attend (n = 6990) Attended (n = 803) Standardized difference (%) Did not attend (n = 802) Attended (n = 802) Standardized difference (%) Men Age in years, mean (SD) 57.6 (13.8) 56.7 (11.7) (11.5) 56.7 (11.7) 2.4 Age category, years: First Nations Healthcare premium subsidy (n = 4,788) (n = 603) (n = 590) (n = 602) status (% of non First Nations under 65 years): No premium subsidy Subsidy Social assistance Care from a primary care network*: Yes No Unknown < 2 general practitioner (GP) claims in 2 years prior to diagnosis diagnosed in hospital Baseline HbA 1c mmol/mol: mean (SD) 60.9 (24.6) 59.7 (20.7) (20.3) 59.7 (20.7) 0.0 %: mean (SD) 7.72 (2.25) 7.61 (1.89) 7.61 (1.86) 7.61 (1.89) Categories: 53 mmol/mol ( 7%) > 53 to < 86 mmol/mol (> 7% to < 10%) mmol/mol ( 10%) Baseline HbA 1c measured in hospital Co morbidities: Affective disorder Cancer Cerebrovascular disease Congestive heart failure Chronic obstructive pulmonary disease Dementia with complications HIV/AIDS Metastatic solid tumour Mild liver disease Moderate/severe liver disease Myocardial infarction Paraplegia or hemiplegia Peptic ulcer disease Peripheral vascular disease Renal disease Rheumatologic disease Charlson Index score, mean (SD) 1.61 (1.26) 1.50 (0.87) (0.85) 1.50 (0.87) 2.3 Values are percentages unless stated otherwise. HIV/AIDS, human immunodeficiency virus/acquired immunodeficiency syndrome. *Primary care networks, which have been shown to be associated with improved glycaemic control [19], consist of general practitioners and other health professionals who collaborate to provide enhanced primary care. participants were matched with non-participants within the specified caliper, resulting in a well-balanced sample, with the mean standardized difference across 37 variables dropping from 10.1% before matching to 3.0% after matching (Table 1). Association between participation and reduction in HbA 1c participation was associated with a significantly greater reduction in unadjusted mean HbA 1c 1612 Diabetic Medicine ª 2014 UK

4 Research article DIABETICMedicine of 3.2 mmol/mol (95% CI ) or 0.29% (95% CI ) and adjusted mean HbA 1c of 3.3 mmol/mol (95% CI ) or 0.30% (95% CI ). The interaction term between baseline HbA 1c and participation was significant, indicating that the adjusted mean difference in change in HbA 1c associated with participation varied with baseline HbA 1c (Fig. 1). The additional reduction in adjusted mean HbA 1c associated with participation ranged from 2.7 mmol/mol (0.25%) at baseline HbA 1c of 53 mmol/mol (7%) to 6.2 mmol/mol (0.56%) at baseline HbA 1c of 97 mmol/mol (11%). Discussion In this population-based cohort of patients with newly diagnosed diabetes, we found that participation in an introductory diabetes education programme ( ) was associated with a significant reduction in adjusted mean HbA 1c of approximately 3.3 mmol/mol (0.3%) at 6 18 months follow-up, with the mean reduction greater among those with higher baseline HbA 1c. Despite the brevity of, the observed reduction in HbA 1c was at the upper end of the range of mmol/mol ( %) reported by several systematic reviews and meta-analyses of didactic diabetes education programmes [3,7,8]. While few trials included in systematic reviews have targeted those with newly diagnosed diabetes, it is possible that the effect of educational interventions may be greater in people with newly diagnosed disease. In addition, the large sample size in this study allowed a more accurate FIGURE 1 Adjusted* difference in change in HbA 1c associated with participation, by level of baseline HbA 1c, among 802 propensity-matched pairs (from regression model). This figure shows significantly greater reductions in mean HbA 1c associated with participation in individuals with higher baseline HbA 1c (P interaction = 0.012). *Adjusted for baseline HbA 1c, age and mean time to follow-up measurement (there was a positive linear association between the mean value of the follow-up measurements and the mean time to the measurements). estimate of the difference in effect size associated with programme participation across a range of baseline HbA 1c than previously reported. Strengths and limitations Strengths of the study include the use of a population-based cohort and propensity score matching to reduce confounding. Limitations include potential misclassification of individuals with diabetes from administrative data, the use of non-standardized HbA 1c measurements and possible residual confounding attributable to unmeasured differences between participants and non-participants. We addressed these concerns through adjustment for baseline HbA 1c, the mean time to follow-up HbA 1c, and proxies for health-seeking motivation, such as the baseline rate of general practitioner (GP) visits, respectively. Implications While the mean reduction in HbA 1c associated with participation was small by clinical standards, it could have important benefits at a population level. Trial data from the UK Prospective Study (UKPDS) found that a 9.8-mmol/mol (0.9%) reduction in HbA 1c in the intensive treatment group compared with the conventional treatment group was associated with a 25% reduction in microvascular endpoints [17]. Assuming a log linear relationship between reduction in HbA 1c and reduction in microvascular endpoints, this implies that a sustained 3.3-mmol/mol (0.3%) reduction in HbA 1c associated with Essential participation would translate to a 9% decrease in the rate of microvascular complications. While we were not able to determine whether the observed reduction in HbA 1c was sustained, 10-year follow-up in the UKPDS suggests that there is a legacy effect of improved glycaemic control early in the natural history of diabetes [18], so even if the improvement in glycaemic control was not sustained, there would likely be benefits from the earlier reduction in HbA 1c. While further investigation is required to confirm the features of the programme resulting in the reduction in HbA 1c of 3.3 mmol/mol (0.3%), and whether this change is sustained over time, these findings have important implications for programme delivery, as is a relatively low-cost intervention that can be readily scaled up for broader delivery. In conclusion, we found that participation in this brief diabetes education programme among newly diagnosed individuals was associated with a significant mean 3.3-mmol/mol (0.3%) reduction in HbA 1c at 6- to 18-months follow-up, with the mean reduction varying by level of baseline HbA 1c. These findings support the delivery of brief diabetes education programmes in newly diagnosed individuals. Diabetic Medicine ª 2014 UK 1613

5 education and glycaemic control R. G. Weaver et al. Funding sources RGW was supported by a training award from the Western Regional Training Centre for Health Services Research. BJM and MT are supported by salary awards from Alberta Innovates Health Solutions (AIHS). BRH is supported by the Roy and Vi Baay Chair in Kidney Research; MT by a Canada Research Chair and MTJ by a KRESCENT new investigator award. This work was supported in part by a team grant from AIHS for the Interdisciplinary Chronic Disease Collaboration. The funders had no role in study design, data collection and analysis, decision to publish or preparation of the manuscript. Competing interests MTJ has received an honorarium for a presentation from Amgen Canada. Acknowledgements This study is based in part on data provided by Alberta Health and Alberta Health Services. The interpretation and conclusions are those of the researchers and do not represent the views of the Government of Alberta. References 1 Canadian Association. Canadian Association 2008 Clinical Practice Guidelines for the Prevention and Management of in Canada. Can J 2008; 32: Chodosh J, Morton SC, Mojica W, Maglione M, Suttorp MJ, Hilton L et al. Meta-analysis: chronic disease self-management programs for older adults. Ann Intern Med 2005; 143: Ellis SE, Speroff T, Dittus RS, Brown A, Pichert JW, Elasy TA. patient education: a meta-analysis and meta-regression. Patient Educ Couns 2004; 52: Gary TL, Genkinger JM, Guallar E, Peyrot M, Brancati FL. Meta-analysis of randomized educational and behavioral interventions in type 2 diabetes. Educ 2003; 29: Minet L, Moller S, Vach W, Wagner L, Henriksen JE. Mediating the effect of self-care management intervention in type 2 diabetes: a meta-analysis of 47 randomised controlled trials. Patient Educ Couns 2010; 80: Norris SL, Lau J, Smith SJ, Schmid CH, Engelgau MM. Self-management education for adults with type 2 diabetes: a meta-analysis of the effect on glycemic control. Care 2002; 25: Tricco AC, Ivers NM, Grimshaw JM, Moher D, Turner L, Galipeau J et al. Effectiveness of quality improvement strategies on the management of diabetes: a systematic review and meta-analysis. Lancet 2012; 379: Shojania KG, Ranji SR, McDonald KM, Grimshaw JM, Sundaram V, Rushakoff RJ, et al. Effects of quality improvement strategies for type 2 diabetes on glycemic control: a meta-regression analysis. J Am Med Assoc 2006; 296: Alberta Health Services. Living Well with a Chronic Condition: Fall 2010 and Winter 2011 Program. Calgary: Alberta Health Services, Hemmelgarn BR, Clement F, Manns BJ, Klarenbach S, James MT, Ravani P et al. Overview of the Alberta Kidney Disease Network. BMC Nephrol 2009; 10: Hux JE, Ivis F, Flintoft V, Bica A. in Ontario: determination of prevalence and incidence using a validated administrative data algorithm. Care 2002; 25: Charlson ME, Pompei P, Ales KL, MacKenzie CR. A new method of classifying prognostic comorbidity in longitudinal studies: development and validation. J Chronic Dis 1987; 40: Quan H, Sundararajan V, Halfon P, Fong A, Burnand B, Luthi JC et al. Coding algorithms for defining comorbidities in ICD-9-CM and ICD-10 administrative data. Med Care 2005; 43: Frayne SM, Miller DR, Sharkansky EJ, Jackson VW, Wang F, Halanych JH et al. Using administrative data to identify mental illness: what approach is best? Am J Med Qual 2010; 25: Rosenbaum PR, Rubin DB. The central role of the propensity score in observational studies for causal effects. Biometrika 1983; 70: Austin PC. Propensity-score matching in the cardiovascular surgery literature from 2004 to 2006: a systematic review and suggestions for improvement. J Thorac Cardiovasc Surg 2007; 134: UKPDS Group. Intensive blood-glucose control with sulphonylureas or insulin compared with conventional treatment and risk of complications in patients with type 2 diabetes (UKPDS 33). UK Prospective Study Group. Lancet 1998; 352: Holman RR, Paul SK, Bethel MA, Matthews DR, Neil HA. 10-year follow-up of intensive glucose control in type 2 diabetes. N Engl J Med 2008; 359: Manns BJ, Tonelli M, Zhang J, Campbell DJ, Sargious P, Ayyalasomayajula B et al. Enrolment in primary care networks: impact on outcomes and processes of care for patients with diabetes. CMAJ 2012; 184: E Diabetic Medicine ª 2014 UK