BACKGROUND: Our goal was to determine whether the prevalence of obesity in children who receive care in Michigan primary care practices is greater than national and state prevalences.
METHODS: We compared prevalences of overweight children and adolescents in primary care practices with the results of the National Health Examination Survey (NHES), the National Health and Nutrition Examination surveys, and a contemporary survey of Michigan schoolchildren. We collected data from 19 rural family practice offices and 2 urban clinics. We measured the heights and weights of 993 consecutive patients aged 4 to 17 years who visited one of the participating practices during the spring of 1996.
RESULTS: Obesity prevalences were the main outcome measure. Of the boys, 38% were above the 85th percentile of the NHES, and 16% were above the 95th percentile. Of the girls, 33% were above the 85th percentile, and 13% were above the 95th percentile. Prevalences of obesity were much higher among the primary care patients than in the results of the national surveys and the contemporary Michigan schoolchildren survey.
CONCLUSIONS: The prevalences of obesity for children and adolescents presenting for care in Michigan primary care practices are higher than the prevalences documented in state and national surveys. A larger systematic study is needed to confirm or refute these findings. If this prevalence of obesity in primary care patients is confirmed, explanations for the differences should be explored.
An increase in the prevalences of childhood and adolescent obesity in the United States has been documented in a series of national surveys conducted in the last 30 years. These include the National Health Evaluation surveys, NHES II (1963-1965) and NHES III (1966-1970), and the National Health and Nutrition Examination surveys, NHANES I (1971-1974), NHANES II (1976-1980), and NHANES III (1988-1994).1-4 Obesity in childhood and adolescence may lead to disorders in adulthood, including hypertension, diabetes, coronary heart disease, and some cancers.5 The strongest connection between chronic disease and death is linked to adolescent rather than adult obesity.6 Between 1980 and 1994 there was a 6% increase in the absolute prevalence of obesity in US children.7 Data from NHANES III, the most recent national survey of weight and height in children and adults, showed that 14% of children aged 6 to 11 years and 12% of those aged 12 to 17 years were overweight.7
We noticed that the prevalence of obesity in our Michigan primary care practices appeared higher than that reported from national or state surveys. We confirmed our impression by measuring a consecutive sample of 6912 patients in 19 practices in the summer of 1996. Analysis of the adult data revealed that 54.5% of the men and 52.6% of the women were overweight, nearly double the prevalences cited in the 1993 Michigan Behavioral Risk Factor Survey (MBRFS): 29.5% for the men and 28.7% for the women.8 MBRFS obesity prevalences are slightly higher than contemporary national prevalences. Comparison with county-specific data from the MBRFS gave the same results. Adjusting the analysis for age, race, socioeconomic status, and chronic diseases associated with obesity such as diabetes and heart disease, did not significantly affect the results. This high prevalence of obesity in primary care patients as compared with population-based surveys has not been previously described, and the reason for it is unknown.
The purpose of our report is to describe the prevalences of obesity in of children and adolescents in our Michigan primary care practices and to compare those prevalences to national and state prevalences. We hypothesized that the children enrolled in our practices would have higher prevalences of obesity than national and state prevalences derived from surveys of community-dwelling populations.
Methods
Practices, Enrollment, and Measurement
We included 19 family practice offices of the Upper Peninsula Research Network (UPRNet) in our study. UPRNet is a family practice research network in rural northern Michigan. These practices are in rural locations, and community populations range from 300 to 15,000. Eleven of the offices are publicly funded community health centers. The populations served are typical of rural northern Michigan, with more than the state average of elderly and poor patients. To include urban and suburban children, we also asked 2 family practice clinics serving middle and lower socioeconomic groups in the Lansing area to participate.
In the spring and early summer of 1996, we invited consecutive patients aged 4 to 17 years visiting any of the participating practices for care to take part in our study, and we obtained informed consent. We chose spring and early summer to avoid those seasons when people wear heavy clothing and boots and to avoid enrolling vacationers who did not reside in the study areas. Patients with appointments specifically to see a dietitian, those known to be pregnant, and those unable to stand on a scale were excluded from the study.