Objective: To determine the relative importance of appropriate prescribing for asthma in explaining high rates of hospital admission for asthma among east London general practices.
Design: Poisson regression analysis describing relation of each general practice's admission rates for asthma with prescribing for asthma and characteristics of general practitioners, practices, and practice populations.
Setting: East London, a deprived inner city area with high admission rates for asthma.
Subjects: All 163 general practices in East London and the City Health Authority (complete data available for 124 practices).
Main outcome measures: Admission rates for asthma, excluding readmissions, for ages 5-64 years; ratio of asthma prophylaxis to bronchodilator prescribing; selected characteristics of general practitioners, practices, and practice populations.
Results: Median admission rate for asthma was 0.9 (range 0-3.6) per 1000 patients per year. Higher admission rates were most strongly associated with small size of practice partnership: admission rates of singlehanded and two partner practices were higher than those of practices with three or more principals by 1.7 times (95% confidence interval 1.4 to 2.0, P < 0.001) and 1.3 times (1.1 to 1.6, P = 0.001) respectively. Practices with higher rates of night visits also had significantly higher admission rates: an increase in night visiting rate by 10 visits per 1000 patients over two years was associated with an increase in admission rates for asthma by 4% (1% to 7%). These associations were independent of asthma prescribing ratios, measures of practice resources, and characteristics of practice populations.
Conclusions: Higher asthma admission rates in east London practices were most strongly associated with smaller partnership size and higher rates of night visiting. Evaluating ways of helping smaller partnerships develop structured proactive care for asthma patients at high risk of admission is a priority.