Hospitalisation rates for ambulatory care sensitive conditions for persons with and without an intellectual disability--a population perspective.

BACKGROUND: There is evidence that persons with an intellectual disability (ID) face barriers to primary care; however, this has not been extensively studied at the population level. Rates of hospitalisation for ambulatory care sensitive conditions are used as an indicator of access to, and quality of, primary care. The objective of the study was to compare hospitalisation rates for ambulatory care sensitive conditions between persons with and without an ID in a publicly insured population.
METHODS: Persons with an ID were identified among the general population of a Canadian province between 1999 and 2003. Using a list of conditions applicable to persons with an ID, rates of hospitalisations for ambulatory care sensitive conditions for persons with and without an ID were calculated and compared. Regression models were used to adjust for age, sex and place of residence. Hospitalisation rates for specific conditions were also compared, controlling for differences in disease prevalence where possible.
RESULTS: Persons with an ID were consistently hospitalised for ambulatory care sensitive conditions at a higher rate than persons without an ID. Between 1999 and 2003 the adjusted rate ratio (RR) was 6.1 [95% confidence interval (CI) = 5.6, 6.7]. Rate ratios were highest when comparing persons with, to persons without, an ID between the ages of 30-39 (RR = 13.1; 95% CI = 10.6, 16.2) and among urban area dwellers (RR = 7.0; 95% CI = 6.2, 7.9). Hospitalisation rates for epilepsy and schizophrenic disorders were, respectively, 54 and 15 times higher for persons with compared with persons without an ID. Rate ratios for diabetes and asthma remained significant after controlling for the population prevalence of these diseases.
CONCLUSIONS: The large discrepancy in rates of hospitalisation between persons with and without an ID is an indicator of inadequate primary care for this vulnerable population. Decreasing the number of ambulatory care sensitive condition hospitalisations through specialised outpatient programmes for persons with an ID would potentially lead to better health, improved quality of life and cost savings. Future research should include potentially important factors such as disease severity, socio-economic variables and measures of health service organisation in the analysis. International comparisons of ambulatory care sensitive condition hospitalisation rates could point to the benefits and limitations of the health service policy directions adopted by different countries.