Epidemiology of Asthma In the Western Michigan Counties of Kent, Montcalm, Muskegon, Newaygo, and Ottawa Elizabeth Wasilevich, MPH Asthma Epidemiologist Bureau of Epidemiology Michigan Department of Community Health 517.335.8164 Publication Date: January 2006 Development and publication of this report was supported by Cooperative Agreement number U59-CCU517742 from the Centers for Disease Control and Prevention (CDC). Its contents are solely the responsibility of the authors and do not necessarily represent the official views of the CDC.
Table of Contents page Section 1: Asthma Prevalence 4 Section 2: Hospitalization for Asthma 6 Total Population, 3-Year Rates 8 Total Population, Annual Rates 9 Sex Stratified, 3-Year Rates 10 Sex Stratified, Annual Rates 11 Race Stratified, 3-Year Rates 12 Race Stratified, Annual Rates 13 Sex and Race Stratified, 3-Year Rates 14 Sex and Race Stratified, Annual Rates 15 Income Stratified, 3-Year Rates 16 Age Stratified (0-4, 5-14, 15-34, 35-64, and 65), 3-Year Rates 17 Age Stratified (0-4, 5-14, 15-34, 35-64, and 65), Annual Rates 18 Age Stratified (<18 and 18), 3-Year Rates 19 Age Stratified (<18 and 18), Annual Rates 20 Total Population by Zip Code, 3-Year Rates 21 Section 3: Asthma Mortality 23 Total Population, 3-Year Rates 24 Total Population, Annual Rates 25 Sex Stratified, 3-Year Rates 26 Race Stratified, 3-Year Rates 27 Age Stratified (<18 and 18), 3-Year Rates 28 Section 4: Healthy People 2010 Objectives for Asthma 29 Hospitalization: Children Aged <18 Years, 3-Year Rates 30 Children Aged <18 Years, Annual Rates 31 Age Stratified (0-4, 5-64, and 65), 3-Year Rates 32 Age Stratified (0-4, 5-64, and 65), Annual Rates 33 Mortality: Age Stratified (0-4, 5-14, 15-34, 35-64, and 65), 3-Year Rates 34 2
Table of Contents (continued) page Section 5: Appendix 35 Hospitalization: Total Population, Annual Rates by County 36 Males, Annual Rates by County 37 Females, Annual Rates by County 38 Whites, Annual Rates by County 39 Blacks, Annual Rates by County 40 White Males, Annual Rates by County 41 White Females, Annual Rates by County 42 Black Males, Annual Rates by County 43 Black Females, Annual Rates by County 44 Children Aged 0-4 Years, Annual Rates by County 45 Children Aged 5-14 Years, Annual Rates by County 46 Children/Adults Aged 15-34 Years, Annual Rates by County 47 Adults Aged 35-64 Years, Annual Rates by County 48 Adults Aged 65 Years, Annual Rates by County 49 Children Aged <18 Years, Annual Rates by County 50 Adults Aged 18 Years, Annual Rates by County 51 Kent County, 3-Year Rates 52 Montcalm County, 3-Year Rates 53 Muskegon County, 3-Year Rates 54 Newaygo County, 3-Year Rates 55 Ottawa County, 3-Year Rates 56 Mortality: Total Population, Annual Rates by County 57 HP 2010 Hospitalization: Children Aged <18 Years, Annual Rates by County 58 Children Aged 0-4 Years, Annual Rates by County 59 Children/Adults Aged 5-64 Years, Annual Rates by County 60 Adults Aged 65 Years, Annual Rates by County 61 Section 6: Data Sources 62 Section 7: Methods 64 3
Section 1: Asthma Prevalence Prevalence is the proportion of individuals in a population who have the disease at a point in time or during a given time period. It is often used to describe the health burden on a given population. Using prevalence estimates of current asthma from the Michigan Behavioral Risk Factor Survey (BRFS), estimates of the number with asthma living in each county are given in this section. Current asthma prevalence is the proportion of survey respondents who reported that in their lifetime a health care professional told them they have asthma and reported yes to the question: Do you still have asthma? The Michigan BRFS is the source of most estimates of the prevalence of certain health behaviors, conditions, and practices associated with leading causes of death. Data are collected quarterly by telephone interview; a sample of telephone numbers is selected using a list-assisted, random-digit dialed methodology. From this survey, the prevalence of asthma can be determined for adults ( 18 years) and children (< 18 years). Data for children are based on information provided by an adult respondent about children living in their home. Due to small sample size, descriptive information regarding children is limited, precluding prevalence analysis by age, race, and sex strata. Data from the BRFS are designed to estimate prevalence statewide. However, using asthma prevalence for the State of Michigan, we can approximate the number of individuals with asthma in specific counties and local coalitions. In this report, the number of adults ( 18 years) with asthma was calculated using the asthma prevalence rates from the 2003 Michigan Behavioral Risk Factor Survey. The number of children with asthma was calculated from the prevalence rates reported in the 2002 Michigan Behavioral Risk Factor Survey. 4
Number of Children (aged less than 18 years) [1] and Adults (aged 18 years and older) [2] with Asthma in Western Michigan [3] and the State of Michigan. Children (<18 Years) Adults ( 18 Years) 2002 2003 Kent 14,944 39,729 Montcalm 1,481 4,355 Muskegon 4,203 11,838 Newaygo 1,244 3,332 Ottawa 6,218 16,896 Western Michigan 28,090 76,150 Michigan 233,894 701,319 1 2 3 Number of children with current asthma was calculated by multiplying the population of children in 2002 by the percentage of adults reporting current asthma for children in the home in the 2002 Michigan BRFS. Number of adults with current asthma was calculated by multiplying the population of adults in 2003 by the percentage reporting current asthma in the 2003 Michigan BRFS. Western Michigan is defined by the Asthma Network of West Michigan coverage area (Kent, Montcalm, Muskegon, Newaygo, Ottawa Counties). Data Source: Behavioral Risk Factor Survey, Michigan, 2002 and 2003 5
Section 2: Hospitalization for Asthma Preventable hospitalizations are those where timely and effective ambulatory care can prevent the onset of an illness or condition, control an acute episode of an illness, or manage a chronic disease or condition so that hospitalization is unnecessary. Asthma hospitalizations are considered preventable because patients with asthma should be able to stay out of the hospital if they have and use good asthma management techniques. Hospitalization data was acquired from the Michigan Inpatient Database for the years 1990 to 2002. All hospital discharges from any of Michigan s reporting acute care hospitals or Michigan residents discharged from reporting acute care hospitals in contiguous states are included in this database. It includes virtually all hospitalizations in Michigan and for Michigan residents during this time period. There is no confirmed case classification for an asthma hospitalization. In accordance with the case definition for a probable asthma hospitalization recommended by the Council for State and Territorial Epidemiologists (CSTE), all inpatient hospitalizations are selected from the database where asthma was the primary reason for the stay. (Position Statement 1998-EH/CD1) These are hospitalizations with primary discharge diagnosis coded to the International Classification of Disease (ICD) Version-9-CM codes 493.XX. These data are the number of inpatient hospitalizations for asthma. This is not the same as the number of individual people hospitalized for asthma. An individual can be hospitalized more than once for the same condition during the study period and multiple hospitalizations cannot be distinguished from this data source. From these data, age-adjusted asthma hospitalization rates are calculated and presented per 10,000 population. Rates are age adjusted so that valid comparisons can be made between populations of different age distributions. Hospitalization rates for demographic or geographic units with a small number of events (less than or equal to 20 events) or a small population size (less than 5,000 population) are not calculated because these rates are statistically unstable. In addition, to protect the identity of persons who have been hospitalized, counts less than 5 are not presented in this report. 6
Ninety five percent confidence intervals are computed for hospitalization rates where more than one year of data are combined. The confidence interval estimates the statistical uncertainty of the asthma hospitalization rate and can be used to test whether a specific measure is statistically different between groups. Average asthma hospitalization rates are considered statistically different between groups if their 95% confidence intervals do not overlap. This technique is used to compare rates for demographic subpopulations, such as male versus female, and geographical subpopulations, such as county versus state. To determine if annual asthma hospitalization rates follow an increasing or decreasing trend over the 13-year period 1990-2002, the Spearman Correlation Coefficient and its accompanying statistical Rank Correlation Test are utilized. This test assesses whether there is a statistically significant monotonic relationship between 2 variables, in this case year and asthma hospitalization rate, without making any assumption about the underlying distribution of the data. This statistical test does not determine the significance of more complex trend patterns. There is no way to know from these statistics if a specific event or series of events caused a change in asthma hospitalization rates. 7
Figure 1. Rates (per 10,000) [1,2] of Hospitalization due to Asthma [3] for Western Michigan [4] and the State of Michigan, All Ages, 2000-2002. 20 Western Michigan Michigan 16 12 Rate 8 4 0 1 Rates are age adjusted to the 2000 US standard population by the direct standardization method. Hospitalization records with missing age are excluded. 2 Population estimates are taken from the Michigan population estimates for 2001. 4 Western Michigan is defined by the Asthma Network of West Michigan coverage area (Kent, Montcalm, Muskegon, Newaygo, Ottawa Counties). Total Population Western MI Rate 9.1 95% CI 8.8, 9.4 Count 3,020 Michigan Rate 15.4 95% CI 15.3, 15.6 Count 45,945 Data Source: Michigan Inpatient Database, Bureau of Epidemiology, MDCH. The average number of hospitalizations due to asthma per year in Western Michigan, 2000-2002, is 1,007. Western Michigan has significantly lower asthma hospitalization rates than the State of Michigan as a whole, 2000-2002. 8
Figure 2. Annual Rates (per 10,000) [1,2] of Asthma [3] Hospitalization, All Ages, for Western Michigan [4], 1990-2002. 14 12 10 Rate 8 6 4 2 0 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 1 Rates are age adjusted to the 2000 US standard population by the direct standardization method. Hospitalization records with missing age are excluded. 2 Population estimates are taken from the Michigan population estimates for 1990-2002. 4 Western Michigan is defined by the Asthma Network of West Michigan coverage area (Kent, Montcalm, Muskegon, Newaygo, Ottawa Counties). Total Population Year Rate Count 1990 12.1 1,165 1991 10.6 1,040 1992 10.8 1,093 1993 12.4 1,260 1994 10.4 1,057 1995 10.8 1,129 1996 11.4 1,204 1997 10.8 1,159 1998 8.8 936 1999 8.8 958 2000 10.1 1,117 2001 8.7 964 2002 8.5 939 Data Source: Michigan Inpatient Database, Bureau of Epidemiology, MDCH. Between 1990 and 2002, there has been a significant overall decrease in asthma hospitalization rates among persons in Western Michigan (ρ = -0.78, p < 0.01). See appendix page 36 for supporting data. 9
Figure 3. Rates (per 10,000) [1,2] of Hospitalization due to Asthma [3] by Sex for Western Michigan [4] and the State of Michigan, All Ages, 2000-2002. 20 Western Michigan Michigan 16 12 Rate 8 4 0 Male Female 1 Rates are age adjusted to the 2000 US standard population by the direct standardization method. Hospitalization records with missing age are excluded. 2 Population estimates are taken from the Michigan population estimates for 2001. 4 Western Michigan is defined by the Asthma Network of West Michigan coverage area (Kent, Montcalm, Muskegon, Newaygo, Ottawa Counties). Male Female Western MI Rate 95% CI 7.2 6.8, 7.6 10.9 10.3, 11.4 Count Michigan Rate 95% CI 1,213 12.9 12.7, 13.1 1,807 17.6 17.4, 17.8 Count 18,987 26,958 Data Source: Michigan Inpatient Database, Bureau of Epidemiology, MDCH. The asthma hospitalization rates for males and females in Western Michigan are significantly lower than the respective rates for the State of Michigan as a whole, 2000-2002. In Western Michigan and the State of Michigan, females have significantly higher asthma hospitalization rates than males, 2000-2002. 10
Figure 4. Annual Rates (per 10,000) [1,2] of Asthma [3] Hospitalization by Sex, All Ages, for Western Michigan [4], 1990-2002. 16 14 Male Female 12 10 Rate 8 6 4 2 0 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 1 Rates are age adjusted to the 2000 US standard population by the direct standardization method. Hospitalization records with missing age are excluded. 2 Population estimates are taken from the Michigan population estimates for 1990-2002. 4 Western Michigan is defined by the Asthma Network of West Michigan coverage area (Kent, Montcalm, Muskegon, Newaygo, Ottawa Counties). Male Female Year Rate Count Rate Count 1990 10.3 512 13.5 653 1991 8.9 452 12.1 588 1992 9.3 484 12.1 608 1993 9.9 522 14.5 737 1994 7.5 397 13.0 660 1995 8.7 467 12.7 662 1996 9.4 514 13.2 690 1997 9.0 495 12.5 664 1998 6.6 363 10.7 572 1999 6.7 377 10.7 580 2000 8.3 467 11.8 650 2001 7.1 397 10.2 567 2002 6.1 349 10.5 590 Data Source: Michigan Inpatient Database, Bureau of Epidemiology, MDCH. Between 1990 and 2002, there has been a significant overall decrease in asthma hospitalization rates among both the male and female populations in Western Michigan (male, ρ = -0.76, p < 0.01; female, ρ = -0.75, p < 0.01). See appendix pages 37 and 38 for supporting data. 11
Figure 5. Rates (per 10,000) [1,2] of Hospitalization due to Asthma [3] by Race [4] for Western Michigan [5] and the State of Michigan, All Ages, 2000-2002. 50 Western Michigan Michigan 40 30 Rate 20 10 0 White Black 1 Rates are age adjusted to the 2000 US standard population by the direct standardization method. Hospitalization records with missing age are excluded. 2 Population estimates are taken from the Michigan population estimates for 2001. 4 For records that are missing data for race, race was assigned based on the 1990 census population for Michigan. 5 Western Michigan is defined by the Asthma Network of West Michigan coverage area (Kent, Montcalm, Muskegon, Newaygo, Ottawa Counties). White Black Western MI Rate 95% CI 8.0 7.7, 8.3 20.7 18.8, 22.5 Count Michigan Rate 95% CI 2,360 10.4 10.3, 10.5 569 43.5 42.9, 44.1 Count 25,455 19,685 Data Source: Michigan Inpatient Database, Bureau of Epidemiology, MDCH. The asthma hospitalization rates for both white persons and black persons in Western Michigan are significantly lower than the respective rates for the State of Michigan as a whole, 2000-2002. The asthma hospitalization rates for white persons in Western Michigan and the State of Michigan are significantly lower than the rates for black persons in respective areas, 2000-2002. While black persons in Western Michigan and the State of Michigan have a higher asthma hospitalization rate, white persons experience the greatest absolute burden of asthma hospitalization. 12
Figure 6. Annual Rates (per 10,000) [1,2] of Asthma [3] Hospitalization by Race [4], All Ages, for Western Michigan [5], 1990-2002. 30 25 White Black 20 Rate 15 10 5 0 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 1 Rates are age adjusted to the 2000 US standard population by the direct standardization method. Hospitalization records with missing age are excluded. 2 Population estimates are taken from the Michigan population estimates for 1990-2002. 4 For records that are missing data for race, race was assigned based on the 1990 census population for Michigan. 5 Western Michigan is defined by the Asthma Network of West Michigan coverage area (Kent, Montcalm, Muskegon, Newaygo, Ottawa Counties). White Black Year Rate Count Rate Count 1990 11.1 978 22.8 170 1991 9.7 853 22.6 179 1992 9.5 859 27.9 217 1993 10.9 997 27.8 229 1994 9.2 838 26.5 191 1995 9.2 863 26.8 223 1996 10.3 964 22.4 188 1997 9.9 946 20.7 185 1998 7.8 743 18.9 167 1999 7.8 761 19.9 178 2000 8.9 873 22.9 211 2001 7.7 757 19.4 179 2002 7.4 730 19.6 179 Data Source: Michigan Inpatient Database, Bureau of Epidemiology, MDCH. Between 1990 and 2002, there has been a significant overall decrease in asthma hospitalization rates among both white persons and black persons in Western Michigan (white, ρ = -0.81, p < 0.01; black, ρ = -0.65, p < 0.05). See appendix pages 39 and 40 for supporting data. 13
Figure 7. Rates (per 10,000) [1,2] of Hospitalization due to Asthma [3] by Sex and Race [4] for Western Michigan [5] and the State of Michigan, All Ages, 2000-2002. 60 Western Michigan Michigan 50 40 Rate 30 20 10 0 White Male White Female Black Male Black Female 1 Rates are age adjusted to the 2000 US standard population by the direct standardization method. Hospitalization records with missing age are excluded. 2 Population estimates are taken from the Michigan population estimates for 2001. 4 For records that are missing data for race, race was assigned based on the 1990 census population for Michigan. 5 Western Michigan is defined by the Asthma Network of West Michigan coverage area (Kent, Montcalm, Muskegon, Newaygo, Ottawa Counties). White Male White Female Black Male Black Female Western MI Rate 95% CI 6.2 5.8, 6.6 9.7 9.2, 10.2 16.7 14.4, 18.9 23.9 21.0, 26.7 Count Michigan Rate 95% CI 910 8.4 8.2, 8.6 1,450 12.2 12.0, 12.4 265 37.1 36.3, 37.9 304 48.0 47.1, 48.9 Count 9,916 15,539 8,702 10,983 Data Source: Michigan Inpatient Database, Bureau of Epidemiology, MDCH. In Western Michigan, the asthma hospitalization rate for black females is significantly higher than the rates among white males, white females, or black males, 2000-2002. In Western Michigan, the asthma hospitalization rate for black persons is significantly higher than the rate among white persons, 2000-2002, regardless of sex. 14
Figure 8. Annual Rates (per 10,000) [1,2] of Asthma [3] Hospitalization by Sex and Race [4], All Ages, for Western Michigan [5], 1990-2002. 40 White Male White Female Black Male Black Female 35 30 25 Rate 20 15 10 5 0 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 1 Rates are age adjusted to the 2000 US standard population by the direct standardization method. Hospitalization records with missing age are excluded. 2 Population estimates are taken from the Michigan population estimates for 1990-2002. 4 For records that are missing data for race, race was assigned based on the 1990 census population for Michigan. 5 Western Michigan is defined by the Asthma Network of West Michigan coverage area (Kent, Montcalm, Muskegon, Newaygo, Ottawa Counties). White Male White Female Black Male Black Female Year Rate Count Rate Count Rate Count Rate Count 1990 9.4 416 12.7 562 21.2 89 23.7 81 1991 8.0 361 11.1 492 19.6 89 24.8 90 1992 8.0 373 10.6 485 23.3 101 31.5 116 1993 8.3 392 13.1 604 25.4 115 29.8 114 1994 6.5 305 11.5 533 17.8 78 33.8 113 1995 7.3 346 11.0 517 22.0 103 30.9 120 1996 8.2 395 12.0 569 20.2 95 24.3 93 1997 8.2 400 11.4 546 17.2 86 23.4 99 1998 5.5 264 10.0 479 17.7 90 19.2 77 1999 5.8 288 9.7 473 18.1 82 21.7 96 2000 7.1 347 10.6 526 19.9 103 25.3 108 2001 6.3 305 9.1 452 15.5 83 22.5 96 2002 5.2 258 9.3 472 14.7 79 23.6 100 Data Source: Michigan Inpatient Database, Bureau of Epidemiology, MDCH. Between 1990 and 2002, there has been a significant overall decrease in asthma hospitalization rates among the white male, white female, and black male populations in Western Michigan (white male, ρ = -0.74, p < 0.01; white female, ρ = -0.74, p < 0.01; black male, ρ = -0.69, p < 0.01). See appendix pages 41 through 44 for supporting data. 15
Figure 9. Rates (per 10,000) [1,2] of Hospitalization due to Asthma [3] by Income [4] for Western Michigan [5], 2000-2002. 20 16 12 Rate 8 4 0 Low Income Middle Income High Income 1 Rates are age adjusted to the 2000 US standard population by the direct standardization method. Hospitalization records with missing age are excluded. 2 Populations are taken from the 2000 US Census. 4 High income = top 20% of Michigan's zip code areas, as determined by median household income from Census 2000; Low income = bottom 20% of Michigan's zip code areas, as determined by median household income from Census 2000; all others are considered middle income. 5 Western Michigan is defined by the Asthma Network of West Michigan coverage area (Kent, Montcalm, Muskegon, Newaygo, Ottawa Counties). Low Income Middle Income High Income Western MI Rate 95% CI 15.1 13.8, 16.3 9.3 8.9, 9.7 6.2 5.7, 6.7 Count 582 2,117 554 Data Source: Michigan Inpatient Database, Bureau of Epidemiology, MDCH. In Western Michigan, the asthma hospitalization rate for low income areas is significantly higher than the rates for high or middle income areas, 2000-2002. 16
Figure 10. Rates (per 10,000) [1] of Hospitalization due to Asthma [2] by Age Group for Western Michigan [3] and the State of Michigan, 2000-2002. 60 50 Western Michigan Michigan 40 Rate 30 20 10 0 0 to 4 5 to 14 15 to 34 35 to 64 65 and older 1 Population estimates are taken from the Michigan population estimates for 2001. 2 Asthma hospitalization is defined as a primary discharge diagnosis of asthma, ICD-9-CM=493.XX. 3 Western Michigan is defined by the Asthma Network of West Michigan coverage area (Kent, Montcalm, Muskegon, Newaygo, Ottawa Counties). 0 to 4 5 to 14 15 to 34 35 to 64 65 and older Western MI Rate 95% CI 24.8 22.8, 26.7 9.1 8.3, 9.9 5.2 4.8, 5.7 8.4 7.9, 8.9 11.1 10.0, 12.2 Count Michigan Rate 95% CI 610 48.5 47.5, 49.5 474 16.7 16.3, 17.0 504 8.4 8.2, 8.6 1,031 13.6 13.4, 13.8 401 16.6 16.2, 17.0 Count 9,637 7,375 6,859 15,964 6,110 Data Source: Michigan Inpatient Database, Bureau of Epidemiology, MDCH. For Western Michigan and the State of Michigan, children aged 0 to 4 years have significantly higher rates of asthma hospitalization than all other age groups, 2000-2002. For Western Michigan and the State of Michigan, persons aged 15 to 34 years have significantly lower rates of asthma hospitalization than all other age groups, 2000-2002. The asthma hospitalization rates for all age groups in Western Michigan are significantly lower than respective rates for the State of Michigan as a whole, 2000-2002. 17
Figure 11. Annual Rates (per 10,000) [1] of Asthma [2] Hospitalization by Age Group for Western Michigan [3], 1990-2002. 50 0 to 4 5 to 14 15 to 34 35 to 64 65 and older 45 40 35 30 Rate 25 20 15 10 5 0 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 1 Population estimates are taken from the Michigan population estimates for 1990-2002. 2 Asthma hospitalization is defined as a primary discharge diagnosis of asthma, ICD-9-CM=493.XX. 3 Western Michigan is defined by the Asthma Network of West Michigan coverage area (Kent, Montcalm, Muskegon, Newaygo, Ottawa Counties). 0 to 4 5 to 14 15 to 34 35 to 64 65 and older Year Rate Count Rate Count Rate Count Rate Count Rate Count 1990 37.3 303 13.7 204 7.0 215 8.9 269 16.5 174 1991 32.5 266 11.5 175 5.5 168 8.4 263 15.6 168 1992 45.0 370 10.8 167 5.3 161 8.2 263 12.0 132 1993 35.9 296 14.9 235 9.0 273 9.1 300 13.9 156 1994 27.8 228 8.5 136 8.4 258 8.3 284 13.2 151 1995 35.0 284 10.4 169 7.9 244 8.8 309 10.6 123 1996 31.2 251 14.4 238 8.4 261 9.2 333 10.4 121 1997 30.0 241 15.1 255 7.4 231 8.1 303 11.0 129 1998 20.8 168 9.1 155 6.5 205 8.0 304 8.8 104 1999 22.3 181 10.1 175 6.2 195 7.9 310 8.2 97 2000 25.6 209 12.5 217 6.5 206 9.0 362 10.3 123 2001 25.1 206 7.7 133 4.5 146 8.4 344 11.2 135 2002 23.7 195 7.2 124 4.7 152 7.8 325 11.8 143 Data Source: Michigan Inpatient Database, Bureau of Epidemiology, MDCH. Between 1990 and 2002, there has been a significant overall decrease in asthma hospitalization rates among the population aged 0 to 4 years and 65 years and older in Western Michigan (0 to 4, ρ = -0.83, p < 0.01; 65 and older, ρ = -0.68, p < 0.05). See appendix pages 45 through 49 for supporting data. 18
Figure 12. Rates (per 10,000) [1,2] of Hospitalization due to Asthma [3] by Age Group for Western Michigan [4] and the State of Michigan, 2000-2002. 30 Western Michigan Michigan 25 20 Rate 15 10 5 0 0 to 17 18 and older 1 Rates are age adjusted to the 2000 US standard population by the direct standardization method. Hospitalization records with missing age are excluded. 2 Population estimates are taken from the Michigan population estimates for 2001. 4 Western Michigan is defined by the Asthma Network of West Michigan coverage area (Kent, Montcalm, Muskegon, Newaygo, Ottawa Counties). 0 to 17 18 and Older Western MI Rate 95% CI 12.6 11.9, 13.3 7.9 7.5, 8.2 Count Michigan Rate 95% CI 1,159 23.9 23.6, 24.3 1,861 12.5 12.3, 12.6 Count 18,141 27,804 Data Source: Michigan Inpatient Database, Bureau of Epidemiology, MDCH. The rates of asthma hospitalization for children less than 18 years of age and adults aged 18 years and older in Western Michigan are significantly lower than the respective rates for the State of Michigan as a whole, 2000-2002. For Western Michigan and the State of Michigan, the rate of asthma hospitalization for children less than 18 years of age is significantly higher than that for adults aged 18 years and older, 2000-2002. 19
Figure 13. Annual Rates (per 10,000) [1,2] of Asthma [3] Hospitalization by Age Group for Western Michigan [4], 1990-2002. 25 0 to 17 18 and older 20 15 Rate 10 5 0 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 1 Rates are age adjusted to the 2000 US standard population by the direct standardization method. Hospitalization records with missing age are excluded. 2 Population estimates are taken from the Michigan population estimates for 1990-2002. 4 Western Michigan is defined by the Asthma Network of West Michigan coverage area (Kent, Montcalm, Muskegon, Newaygo, Ottawa Counties). 0 to 17 18 and Older Year Rate Count Rate Count 1990 18.9 534 9.7 631 1991 16.6 475 8.6 565 1992 19.1 560 7.9 533 1993 19.4 567 9.9 693 1994 14.5 424 9.0 633 1995 16.9 500 8.7 629 1996 18.1 537 9.1 667 1997 17.7 530 8.5 629 1998 11.6 349 7.8 587 1999 12.4 379 7.5 579 2000 15.1 462 8.4 655 2001 11.7 359 7.7 605 2002 11.0 338 7.6 601 Data Source: Michigan Inpatient Database, Bureau of Epidemiology, MDCH. Between 1990 and 2002, there has been a significant overall decrease in asthma hospitalization rates for both age groups in Western Michigan (less than 18, ρ = -0.75, p < 0.01; 18 and older, ρ = -0.72, p < 0.01). See appendix pages 50 and 51 for supporting data. 20
Rates (per 10,000) [1,2] of Hospitalization due to Asthma [3] by Zip Code of Residence, Western Michigan [4], All Ages, 2000-2002. 95% Confidence Interval Zip Code Count Rate Lower Limit Upper Limit 48809 18 48811 11 48815 ~ 48818 16 48829 8 48834 10 48838 43 8.8 6.1 11.4 48845 6 48850 10 48852 ~ 48877 11 48884 11 48885 6 48886 7 48888 20 48891 18 49301 13 49302 ~ 49303 ~ 49306 8 49307 28 6.1 3.8 8.4 49309 10 49310 11 49312 ~ 49315 21 5.2 2.9 7.4 49316 20 49318 ~ 49319 38 9.9 6.6 13.1 49321 32 7.0 4.5 9.5 49322 ~ 49325 6 49326 5 49327 37 17.5 11.8 23.2 49329 20 49330 16 49331 16 49333 20 49336 10 49337 24 6.4 3.8 9.1 49338 5 49339 5 49341 28 3.2 2.0 4.5 49343 11 49345 27 7.6 4.7 10.5 49346 11 49347 ~ 49348 25 6.9 4.2 9.6 49349 24 10.1 6.0 14.2 49401 24 9.3 5.2 13.5 Note: Table continued on next page. 21
(continued from previous page) 49403 ~ 49404 6 49412 21 6.2 3.5 8.9 49415 14 49417 32 3.9 2.5 5.2 49418 55 7.5 5.5 9.5 49421 17 49423 154 11.3 9.5 13.1 49424 92 7.6 5.9 9.2 49425 ~ 49426 48 6.2 4.4 8.0 49428 41 5.7 3.9 7.4 49434 ~ 49435 6 49437 7 49440 ~ 49441 83 6.9 5.4 8.4 49442 189 13.4 11.5 15.3 49444 130 19.6 16.2 23.0 49445 37 6.4 4.3 8.5 49448 ~ 49451 14 49456 32 6.1 3.9 8.2 49457 19 49459 7 49460 17 49461 10 49464 59 9.2 6.8 11.5 49503 194 20.6 17.6 23.6 49504 159 13.3 11.2 15.4 49505 134 14.2 11.8 16.7 49506 109 10.8 8.7 12.8 49507 258 21.7 18.8 24.6 49508 137 11.3 9.4 13.2 49509 176 10.3 8.8 11.9 49512 18 49525 32 4.3 2.8 5.8 49544 62 7.6 5.7 9.6 49546 52 5.0 3.6 6.4 49548 108 11.5 9.3 13.7 49677 7 Western MI 3,020 9.1 8.8 9.4 1 Rates are age adjusted to the 2000 US standard population by the direct standardization method. Hospitalization records with missing age are excluded. 2 Populations are taken from the 2000 US Census. 4 Western Michigan is defined by the Asthma Network of West Michigan coverage area (Kent, Montcalm, Muskegon, Newaygo, Ottawa Counties). Insufficient data to compute a stable rate (number of events 20 or population <5000). ~ Number of hospitalizations <5. Data Source: Michigan Inpatient Database, Bureau of Epidemiology, MDCH. 22
Section 3: Asthma Mortality Successful asthma management reduces symptoms and improves quality of life. Failure to maintain good control of the disease results in a higher risk of mortality. Death due to asthma is a rare and preventable event, indicative of difficulty in selfmanagement and/or access to care. Mortality data are acquired from the Michigan Resident Death Files for the years 1990 to 2003. This database includes all deaths in Michigan and deaths of Michigan residents where the death occurred out-of-state. As recommended by the Council for State and Territorial Epidemiologists (Position Statement 1998-EH/CD 1), deaths where asthma is primary cause are selected from these data. From 1990 to 1998, these are deaths with primary cause coded to International Classification of Disease (ICD) Version-9 codes 493.XX. Deaths occurring from 1999 to 2003 are classified according to ICD Version 10; ICD-10 codes for asthma are J45 and J46. The ICD-10 coding scheme is different and more detailed than its predecessor, ICD-9. Deaths coded with ICD-10 are not directly comparable to deaths coded with ICD-9. While a comparability ratio between ICD-9 and ICD-10 exists for asthma (0.8938; that is, for every 100 asthma deaths coded with ICD-9, only 89.38 would be coded as asthma using ICD-10), the analysis presented here does not attempt to compare pre- 1999 data with asthma death occuring since 1999. (Anderson RN, et al. National Vital Statistics Reports; 49(2). 2001) Age-adjusted asthma mortality rates are calculated and presented per 1,000,000 population. Rates are age adjusted so that valid comparisons can be made between populations of different age distributions. Mortality rates for demographic units with a small number of events (less than 5 events) or a small population size (less than 5,000 population) are not calculated because these rates are statistically unstable. In addition, to protect the identity of the deceased, counts less than 5 are not presented in this report. Ninety five percent confidence intervals are computed for asthma mortality rates where more than one year of data are combined. The confidence interval estimates the statistical uncertainty of the mortality rate and can be used to test whether rates are statistically different between groups. Average asthma mortality rates are considered statistically different between groups if their 95% confidence intervals do not overlap. This technique is used to compare rates for demographic subpopulations, such as male versus female, and geographical subpopulations, such as county versus state. Due to the difference in asthma mortality coding between pre-1999 and 1999-present data, trend analyses were not conducted. 23
Figure 14. Rates (per 1,000,000) [1,2] of Mortality due to Asthma [3] for Western Michigan [4] and the State of Michigan, All Ages, 2001-2003. 20 Western Michigan Michigan 16 12 Rate 8 4 0 1 Rates are age adjusted to the 2000 US standard population by the direct standardization method. 2 Population estimates are taken from the Michigan population estimates for 2002. 3 Asthma death is defined as a primary cause of death as asthma, ICD-10=J45 or J46. 4 Western Michigan is defined by the Asthma Network of West Michigan coverage area (Kent, Montcalm, Muskegon, Newaygo, Ottawa Counties). Total Population Western MI Rate 9.9 95% CI 6.4, 13.4 Count 31 Michigan Rate 14.6 95% CI 13.2, 16.0 Count 441 Data Source: Michigan Resident Death Files, Bureau of Epidemiology, MDCH. The average number of deaths due to asthma per year in Western Michigan, 2001-2003, is 10. The rate of asthma mortality in Western Michigan is lower than the rate for the State of Michigan as a whole, 2001-2003, though not significantly. 24
Figure 15. Annual Rates (per 1,000,000) [1,2] of Mortality due to Asthma [3], All Ages, for Western Michigan [4], 1990-2002 [5]. Rate 35 30 25 20 15 10 5 0 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 1 Rates are age adjusted to the 2000 US standard population by the direct standardization method. 2 Population estimates are taken from the Michigan population estimates for 1990-2002. 3 Asthma death is defined as a primary cause of death as asthma, ICD-9=493.XX and ICD-10=J45 or J46. 4 Western Michigan is defined by the Asthma Network of West Michigan coverage area (Kent, Montcalm, Muskegon, Newaygo, Ottawa Counties). 5 Due to a change in coding for asthma deaths beginning in 1999, rates calculated for 1999-2002 are not comparable to rates calculated for 1990-1998. Total Population Year Rate Count 1990 22.9 20 1991 21.2 18 1992 21.6 18 1993 31.0 27 1994 19.8 18 1995 17.7 16 1996 25.7 23 1997 14.0 13 1998 14.4 14 1999 13.4 13 2000 13.9 14 2001 6.0 6 2002 6.6 7 Data Source: Michigan Resident Death Files, Bureau of Epidemiology, MDCH. See appendix page 57 for supporting data. 25
Figure 16. Rates (per 1,000,000) [1,2] of Mortality due to Asthma [3] by Sex for Western Michigan [4] and the State of Michigan, All Ages, 2001-2003. 20 Western Michigan Michigan 16 12 Rate 8 4 0 Male Female 1 Rates are age adjusted to the 2000 US standard population by the direct standardization method. 2 Population estimates are taken from the Michigan population estimates for 2002. 3 Asthma death is defined as a primary cause of death as asthma, ICD-10=J45 or J46. 4 Western Michigan is defined by the Asthma Network of West Michigan coverage area (Kent, Montcalm, Muskegon, Newaygo, Ottawa Counties). Male Female Western MI Rate 95% CI 7.4 2.9, 11.9 11.5 6.4, 16.6 Count Michigan Rate 95% CI 11 12.6 10.7, 14.5 20 16.1 14.1, 18.0 Count 171 270 Data Source: Michigan Resident Death Files, Bureau of Epidemiology, MDCH. For Western Michigan and the State of Michigan, the rate of asthma mortality for females is not significantly different than the rate for males, 2001-2003. 26
Figure 17. Rates (per 1,000,000) [1,2] of Mortality due to Asthma [3] by Race for Western Michigan [4] and the State of Michigan, All Ages, 2001-2003. 60 Western Michigan Michigan 50 40 Rate 30 20 10 0 White Black 1 Rates are age adjusted to the 2000 US standard population by the direct standardization method. 2 Population estimates are taken from the Michigan population estimates for 2002. 3 Asthma death is defined as a primary cause of death as asthma, ICD-10=J45 or J46. 4 Western Michigan is defined by the Asthma Network of West Michigan coverage area (Kent, Montcalm, Muskegon, Newaygo, Ottawa Counties). White Black Western MI Rate 95% CI 8.7 5.3, 12.1 24.5 1.3, 47.7 Count Michigan Rate 95% CI 25 10.5 9.2, 11.7 5 41.1 34.7, 47.6 Count 273 163 Data Source: Michigan Resident Death Files, Bureau of Epidemiology, MDCH. While black persons in the State of Michigan have a significantly higher asthma mortality rate, white persons experience more asthma related deaths, 2001-2003. 27
Figure 18. Rates (per 1,000,000) [1,2] of Mortality due to Asthma [3] by Age Group for Western Michigan [4] and the State of Michigan, 2001-2003. 25 Western Michigan Michigan 20 15 Rate 10 5 0 0 to 17 18 and older 1 Rates are age adjusted to the 2000 US standard population by the direct standardization method. 2 Population estimates are taken from the Michigan population estimates for 2002. 3 Asthma death is defined as a primary cause of death as asthma, ICD-10=J45 or J46. 4 Western Michigan is defined by the Asthma Network of West Michigan coverage area (Kent, Montcalm, Muskegon, Newaygo, Ottawa Counties). 0 to 17 18 and Older Western MI Rate 95% CI, 12.6 8.0, 17.2 Count Michigan Rate 95% CI ~ 4.4 3.0, 5.9 29 18.1 16.4, 19.9 Count 35 406 Insufficient data to compute a stable rate (number of events <5 or population <5000). ~ Due to a low number of events (<5), results are suppressed to protect the identity of the deceased. Data Source: Michigan Resident Death Files, Bureau of Epidemiology, MDCH. The asthma mortality rate in the State of Michigan is significantly higher for individuals aged 18 years and older than for individuals aged less than 18 years, 2001-2003. 28
Section 4: Healthy People 2010 Objectives for Asthma The U.S. Department of Health and Human Services has developed Healthy People 2010, a set of disease prevention and health promotion objectives for the nation to achieve over the first decade of the new century. Although neither the United States nor Michigan have met all the Healthy People 2010 targets for asthma, Michigan has had some success in reaching particular asthma objectives for some populations. For more information about the Healthy People 2010 initiative, visit their website: http://www.healthypeople.gov. The following asthma hospitalization and mortality figures provide information for Kent, Montcalm, Muskegon, Newaygo, and Ottawa Counties, Western Michigan, and the State of Michigan, as compared to the Healthy People 2010 targets for asthma. Selected Healthy People 2010 Objectives Related to Asthma for which Western Michigan Data are Available for Comparison. Objective 1-9a: Reduce hospitalization rates for three ambulatory-care-sensitive conditions: pediatric asthma, uncontrolled diabetes, and immunization preventable pneumonia and influenza. Target: 17.3 per 10,000 (age 0-17 years) Objective 24-1: Reduce asthma deaths. Targets: 1 per 1,000,000 (age 0-4 years) 1 per 1,000,000 (age 5-14 years) 2 per 1,000,000 (age 15-34 years) 9 per 1,000,000 (age 35-64 years) 60 per 1,000,000 (age 65 years) Objective 24-2: Reduce hospitalizations for asthma. Targets: 25 per 10,000 (age 0-4 years) 7.7 per 10,000 (age 5-64 years*) 11 per 10,000 (age 65 years*) *Age adjusted to the 2000 U.S. standard population. 29
Figure 19. Rates (per 10,000) [1,2] of Hospitalization due to Asthma [3] for Children (aged less than 18 years) in Western Michigan [4] and the State of Michigan, 2000-2002, Compared to the Healthy People 2010 Target (Objective 1-9a). 30 Western Michigan Michigan HP 2010 Target 25 20 Rate 15 10 5 0 1 Population estimates are taken from the Michigan population estimates for 2001. 2 Not age adjusted in accordance with analysis prescribed by Healthy People 2010 Objectives. 4 Western Michigan is defined by the Asthma Network of West Michigan coverage area (Kent, Montcalm, Muskegon, Newaygo, Ottawa Counties). Total Population Western MI Rate 12.5 95% CI 11.8, 13.2 Count 1,159 Michigan Rate 23.5 95% CI 23.2, 23.8 Count 18,141 HP 2010 Target 17.3 Data Source: Michigan Inpatient Database, Bureau of Epidemiology, MDCH. The average number of hospitalizations due to asthma per year for children aged less than 18 years in Western Michigan, 2000-2002, is 386. The rate of asthma hospitalization for children aged less than 18 years in Western Michigan, 2000-2002, is significantly lower than the Healthy People 2010 objective. 30
Figure 20. Annual Rates (per 10,000) [1,2] of Asthma [3] Hospitalization for Children (aged less than 18 years) in Western Michigan [4], 1990-2002, Compared to the Healthy People 2010 Target (Objective 1-9a). 25 0 to 17 HP 2010 Target 20 15 Rate 10 5 0 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 1 Population estimates are taken from the Michigan population estimates for 1990-2002. 2 Not age adjusted in accordance with analysis prescribed by Healthy People 2010 Objectives. 4 Western Michigan is defined by the Asthma Network of West Michigan coverage area (Kent, Montcalm, Muskegon, Newaygo, Ottawa Counties). 0 to 17 Year Rate Count 1990 19.9 534 1991 17.3 475 1992 20.1 560 1993 20.0 567 1994 14.8 424 1995 17.2 500 1996 18.2 537 1997 17.7 530 1998 11.6 349 1999 12.4 379 2000 15.0 462 2001 11.6 359 2002 10.9 338 HP 2010 Target 17.3 Data Source: Michigan Inpatient Database, Bureau of Epidemiology, MDCH. Between 1990 and 2002, there has been a significant overall decrease in asthma hospitalization rates among persons aged less than 18 years in Western Michigan (ρ = -0.78, p < 0.01). See appendix page 58 for supporting data. 31
Figure 21. Rates (per 10,000) [1,2] of Hospitalization due to Asthma [3] by Age Group for Western Michigan [4] and the State of Michigan, 2000-2002, Compared to the Healthy People 2010 Targets (Objective 24-2). 60 Western Michigan Michigan HP 2010 Target 50 40 Rate 30 20 10 0 0 to 4 5 to 64 65 and older 1 For age group 5-64 years and age group 65 and older, rates are age adjusted to the 2000 US standard population by the direct standardization method. Hospitalization records with missing age are excluded. 2 Population estimates are taken from the Michigan population estimates for 2001. 4 Western Michigan is defined by the Asthma Network of West Michigan coverage area (Kent, Montcalm, Muskegon, Newaygo, Ottawa Counties). 0 to 4 5 to 64 65 and Older Western MI Rate 95% CI 24.8 22.8, 26.7 7.5 7.1, 7.8 11.0 10, 12.1 Count Michigan Rate 95% CI 610 48.5 47.5, 49.5 2,009 12.4 12.2, 12.5 401 16.6 16.2, 17.0 Count 9,637 30,198 6,110 HP 2010 Target 25.0 7.7 11.0 Data Source: Michigan Inpatient Database, Bureau of Epidemiology, MDCH. For all age groups, the rates of asthma hospitalization in Western Michigan are not significantly different than the respective Healthy People 2010 Target Rates, 2000-2002. For all age groups, the rates of asthma hospitalization in Western Michigan are significantly lower than the respective rates for Michigan as a whole, 2000-2002. 32
Figure 22. Annual Rates (per 10,000) [1,2] of Asthma [3] Hospitalization by Age Group for Western Michigan [4], 1990-2002, Compared to the Healthy People 2010 Targets (Objective 24-2). 50 0 to 4 5 to 64 65 and older 45 40 35 30 Rate 25 20 15 10 5 0 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 1 For age group 5-64 years and age group 65 and older, rates are age adjusted to the 2000 US standard population by the direct standardization method. Hospitalization records with missing age are excluded. 2 Population estimates are taken from the Michigan population estimates for 1990-2002. 4 Western Michigan is defined by the Asthma Network of West Michigan coverage area (Kent, Montcalm, Muskegon, Newaygo, Ottawa Counties). 0 to 4 5 to 64 65 and Older Year Rate Count Rate Count Rate Count 1990 37.3 303 9.2 688 16.4 174 1991 32.5 266 8.0 606 15.6 168 1992 45.0 370 7.7 591 12.2 132 1993 35.9 296 10.1 808 14.0 156 1994 27.8 228 8.5 678 13.4 151 1995 35.0 284 8.8 722 10.7 123 1996 31.2 251 9.9 832 10.5 121 1997 30.0 241 9.2 789 11.0 129 1998 20.8 168 7.7 664 8.8 104 1999 22.3 181 7.7 680 8.2 97 2000 25.6 209 8.8 785 10.3 123 2001 25.1 206 7.0 623 11.2 135 2002 23.7 195 6.6 601 11.7 143 HP 2010 Target 25.0 7.7 11.0 Data Source: Michigan Inpatient Database, Bureau of Epidemiology, MDCH. Between 1990 and 2002, there has been a significant decrease in asthma hospitalization rates for persons aged 0 to 4 years and 65 years and older in Western Michigan (0 to 4 years, ρ = -0.83, p < 0.01; 65 and older, ρ = -0.68, p < 0.05). See appendix pages 59 through 61 for supporting data. 33
Figure 23. Rates (per 1,000,000) [1] of Mortality due to Asthma [2] by Age Group for Western Michigan [3] and the State of Michigan, 2001-2003, Compared to the Healthy People 2010 Targets (Objective 24-1). 70 Western Michigan Michigan HP 2010 Target 60 50 Rate 40 30 20 10 0 0 to 4 5 to 14 15 to 34 35 to 64 65 and older 1 Population estimates are taken from the Michigan population estimates for 2002. 2 Asthma death is defined as a primary cause of death as asthma, ICD-10=J45 or J46. 3 Western Michigan is defined by the Asthma Network of West Michigan coverage area (Kent, Montcalm, Muskegon, Newaygo, Ottawa Counties). 0 to 4 5 to 14 15 to 34 35 to 64 65 and Older Western MI Rate 95% CI,,, 8.0 3.0, 12.9 41.3 20.4, 62.1 Count Michigan Rate 95% CI ~, ~ 4.3 2.4, 6.3 ~ 7.7 5.8, 9.6 10 14.2 12.0, 16.3 15 50.6 43.3, 57.9 Count ~ 19 63 168 187 HP 2010 Target 1.0 1.0 2.0 9.0 60.0 Insufficient data to compute a stable rate (number of events <5 or population <5000). ~ Due to a low number of events (<5), results are suppressed to protect the identity of the deceased. Data Source: Michigan Resident Death Files, Bureau of Epidemiology, MDCH. The rate of asthma mortality in the State of Michigan is significantly higher than the Healthy People 2010 Target Rate for the 5 to 14, 15 to 34, and 35 to 64 year age groups, 2001-2003. The rate of asthma mortality in the State of Michigan is significantly lower than the Healthy People 2010 Target Rate for the 65 years and older age group, 2001-2003. 34
Section 5: Appendix This appendix includes a compilation of supporting data tables presenting annual hospitalization and mortality rates for Kent, Montcalm, Muskegon, Newaygo, and Ottawa Counties, Western Michigan, and the State of Michigan. It also includes a summary for each Western Michigan county of 3-year hospitalization rates by age, race, and sex strata. 35
Counts and Rates (per 10,000) [1,2] of Asthma [3] Hospitalization [4] by Year, All Ages, for Kent, Montcalm, Muskegon, Newaygo, and Ottawa Counties, Western Michigan [5], and the State of Michigan, 1990-2002. Year Kent Montcalm Muskegon Newaygo Ottawa Western MI Michigan Rate Count Rate Count Rate Count Rate Count Rate Count Rate Count Rate Count 1990 12.1 626 12.5 66 13.4 218 10.3 41 11.5 214 12.1 1,165 19.1 17,790 1991 11.5 599 8.7 48 13.0 214 9.5 41 7.4 138 10.6 1,040 18.1 16,995 1992 12.0 648 9.6 53 10.9 184 12.0 52 8.0 156 10.8 1,093 18.4 17,597 1993 14.0 758 12.9 72 10.4 177 12.4 54 9.8 199 12.4 1,260 19.8 18,975 1994 11.4 612 9.2 51 8.7 145 10.6 47 9.8 202 10.4 1,057 18.4 17,609 1995 11.9 656 14.2 81 10.9 183 6.7 30 8.5 179 10.8 1,129 19.5 18,945 1996 13.4 747 15.8 92 9.8 166 6.0 27 7.9 172 11.4 1,204 18.5 18,058 1997 13.1 743 10.5 62 8.0 136 7.7 34 8.5 184 10.8 1,159 17.7 17,320 1998 10.3 580 8.2 48 7.5 126 6.5 30 6.7 152 8.8 936 15.6 15,289 1999 9.3 530 7.8 47 11.0 187 6.1 29 7.2 165 8.8 958 15.6 15,385 2000 10.6 616 9.0 55 11.5 196 10.1 48 8.5 202 10.1 1,117 16.0 15,886 2001 9.5 549 11.3 69 9.2 157 8.5 40 6.3 149 8.7 964 15.5 15,363 2002 9.4 551 9.4 57 9.5 163 7.3 35 5.7 133 8.5 939 14.7 14,696 Spearman's ρ 0.67 0.25 0.44 0.52 0.66 0.78 0.79 1 Population estimates are taken from the Michigan population estimates for 1990-2002. 2 Rates are age adjusted to the 2000 US standard population by the direct standardization method. Hospitalization records with missing age are excluded. 4 Data Source: Michigan Inpatient Database, Bureau of Epidemiology, MDCH. 5 Western Michigan is defined by the Asthma Network of West Michigan coverage area (Kent, Montcalm, Muskegon, Newaygo, Ottawa Counties). * Correlation is statistically significant; p-value < 0.05. Correlation is statistically significant; p-value < 0.01. ** Sample Interpretation of Annual Rate: In 2002, the rate of asthma hospitalization in Michigan was 14.7 per 10,000 population. Sample Trend Interpretation: Between 1990 and 2002, there has been a significant overall decrease in asthma hospitalization rates in Michigan. 36
Counts and Rates (per 10,000) [1,2] of Asthma [3] Hospitalization [4] by Year for MALES All Ages, for Kent, Montcalm, Muskegon, Newaygo, and Ottawa Counties, Western Michigan [5], and the State of Michigan, 1990-2002. Year Kent Montcalm Muskegon Newaygo Ottawa Western MI Michigan Rate Count Rate Count Rate Count Rate Count Rate Count Rate Count Rate Count 1990 10.7 280 8.1 23 11.3 96 10.9 21 9.4 92 10.3 512 17.1 7,951 1991 9.7 259 8.3 24 11.2 96 9.3 21 5.3 52 8.9 452 15.7 7,345 1992 9.6 272 9.7 28 9.4 81 12.0 27 7.6 76 9.3 484 16.1 7,666 1993 10.8 300 11.8 35 9.4 83 20 7.8 84 9.9 522 16.6 7,929 1994 8.2 233 15 7.0 60 17 7.1 72 7.5 397 15.4 7,339 1995 9.3 269 14.0 41 8.9 78 15 6.2 64 8.7 467 17.1 8,275 1996 10.7 313 11.8 36 9.7 84 15 6.2 66 9.4 514 15.9 7,725 1997 10.4 309 8.7 27 7.2 63 15 7.5 81 9.0 495 15.4 7,546 1998 7.6 222 11 6.8 58 13 5.2 59 6.6 363 12.7 6,199 1999 7.0 207 16 9.1 79 14 5.3 61 6.7 377 12.7 6,229 2000 8.4 250 7.5 23 11.1 96 11 7.1 87 8.3 467 13.7 6,745 2001 7.9 234 8.5 26 6.7 58 13 5.7 66 7.1 397 12.8 6,271 2002 6.9 211 7.5 22 6.8 59 9 4.1 48 6.1 349 12.2 5,971 Spearman's ρ 0.72 ψ 0.64 ψ 0.66 0.76 0.82 1 Population estimates are taken from the Michigan population estimates for 1990-2002. 2 Rates are age adjusted to the 2000 US standard population by the direct standardization method. Hospitalization records with missing age are excluded. 4 Data Source: Michigan Inpatient Database, Bureau of Epidemiology, MDCH. 5 Western Michigan is defined by the Asthma Network of West Michigan coverage area (Kent, Montcalm, Muskegon, Newaygo, Ottawa Counties). Insufficient data to compute a stable rate (number of events 20 or population <5000). * Correlation is statistically significant; p-value < 0.05. ** Correlation is statistically significant; p-value < 0.01. ψ Insufficient data to compute Spearman Correlation Coefficient. Sample Interpretation of Annual Rate: In 2002, the rate of asthma hospitalization among males in Michigan was 12.2 per 10,000 population. Sample Trend Interpretation: Between 1990 and 2002, there has been a significant overall decrease in asthma hospitalization rates for males in Michigan. 37
Counts and Rates (per 10,000) [1,2] of Asthma [3] Hospitalization [4] by Year for FEMALES, All Ages, for Kent, Montcalm, Muskegon, Newaygo, and Ottawa Counties, Western Michigan [5], and the State of Michigan, 1990-2002. Year Kent Montcalm Muskegon Newaygo Ottawa Western MI Michigan Rate Count Rate Count Rate Count Rate Count Rate Count Rate Count Rate Count 1990 13.2 346 16.9 43 15.2 122 20 13.2 122 13.5 653 20.6 9,834 1991 13.0 340 8.9 24 14.4 118 20 9.2 86 12.1 588 20.0 9,648 1992 13.8 376 8.9 24 12.4 103 11.8 25 8.2 80 12.1 608 20.3 9,927 1993 16.9 458 13.7 36 11.0 94 16.1 34 11.2 115 14.5 737 22.6 11,043 1994 14.0 379 13.5 36 10.0 85 13.5 30 12.3 130 13.0 660 20.9 10,269 1995 14.0 387 14.4 40 12.7 105 15 10.6 115 12.7 662 21.6 10,668 1996 15.7 434 20.1 56 9.9 82 12 9.4 106 13.2 690 20.8 10,333 1997 15.4 434 12.6 35 8.7 73 19 9.0 103 12.5 664 19.6 9,774 1998 12.7 357 13.1 37 8.1 68 17 8.2 93 10.7 572 18.1 9,089 1999 11.3 322 10.8 31 12.7 108 15 9.0 104 10.7 580 18.1 9,155 2000 12.6 366 10.8 32 11.9 100 15.5 37 9.6 115 11.8 650 18.0 9,141 2001 10.8 315 14.7 43 11.6 99 11.4 27 6.9 83 10.2 567 17.8 9,092 2002 11.6 340 12.0 35 12.0 104 10.6 26 7.0 85 10.5 590 16.9 8,725 Spearman's ρ 0.58 0.05 0.36 ψ 0.62 0.75 0.76 1 Population estimates are taken from the Michigan population estimates for 1990-2002. 2 Rates are age adjusted to the 2000 US standard population by the direct standardization method. Hospitalization records with missing age are excluded. 4 Data Source: Michigan Inpatient Database, Bureau of Epidemiology, MDCH. 5 Western Michigan is defined by the Asthma Network of West Michigan coverage area (Kent, Montcalm, Muskegon, Newaygo, Ottawa Counties). Insufficient data to compute a stable rate (number of events 20 or population <5000). * Correlation is statistically significant; p-value < 0.05. ** Correlation is statistically significant; p-value < 0.01. ψ Insufficient data to compute Spearman Correlation Coefficient. Sample Interpretation of Annual Rate: In 2002, the rate of asthma hospitalization among females in Michigan was 16.9 per 10,000 population. Sample Trend Interpretation: Between 1990 and 2002, there has been a significant overall decrease in asthma hospitalization rates for females in Michigan. 38