Association of population and primary healthcare factors with hospital admission rates for chronic obstructive pulmonary disease in England: national cross-sectional study

BackgroundHospital admission rates for chronic obstructive pulmonary disease (COPD) are known to be strongly associated with population factors. Primary care services may also affect admission rates, but there is little direct supporting evidence.ObjectivesTo determine associations between population characteristics, diagnosed and undiagnosed COPD prevalence, primary healthcare factors, and COPD admission rates primary care trust (PCT) and general practice levels in England.Design, setting, and participantsNational cross-sectional study (53,676,051 patients in 8,064 practices in 152 English PCTs), combining data on hospital admissions, populations, primary healthcare staffing, clinical practice quality and access, and prevalence.Main outcome measuresDirectly and indirectly standardised hospital admission rates for COPD, for PCT and practice populations.ResultsMean annual COPD admission rates per 100 000 population varied from 124.7 to 646.5 for PCTs and 0.0 to 2175.2 for practices. Admissions were strongly associated with population deprivation at both levels. In a practice-level multivariate Poisson regression, registered and undiagnosed COPD prevalence, smoking prevalence and deprivation were risk factors for admission (p