Relation of rates of self referral to A&E departments to deprivationBMJ 1998; 317 doi: https://doi.org/10.1136/bmj.317.7157.538 (Published 22 August 1998) Cite this as: BMJ 1998;317:538
Robust markers are needed of variations in case mix among practices
- Sally Hull, Senior lecturer, department of general practice.,
- Ian Rees Jones, Lecturer, department of geography.,
- Kath Moser, Research officer, department of general practice.
EDITOR—Carlisle et al report an association between markers of social deprivation derived from the 1991 census and out of hours contacts with both general practice services and accident and emergency departments.1
We undertook a related study in east London, based on 63 000 attendances by adults at accident and emergency departments.2 This showed that factors related to social deprivation accounted for 48% of the variation in total adult attendance rates between practices. This was so even in an area of consistently high deprivation where the practices' underprivileged area (Jarman) scores ranged from 30.4 to 62.1 (median value 42.5). In contrast to Carlisle et al, we included in the multivariate analysis explanatory variables relating to practice size and resources, since organisational factors are often cited as causes of high use of accident and emergency departments among inner city populations.3 We found that practice characteristics (partnership size, female partner, practice manager, nurse, training status, and computer) did not predict rates of attendance, while markers of deprivation did. Distance from the hospital was negatively correlated with attendance rates in the univariate analysis but not in the multivariate analysis.
Carlisle et al's paper mentioned another intriguing finding: wide variation in out of hours use of both general practitioners and accident and emergency departments between practices serving populations from the same wards. We recently completed a study examining the outcomes of all attendances at an accident and emergency department by patients from two practices over seven months.4 The practices were in Tower Hamlets, had similar underprivileged area scores, were in close proximity to each other, and were within 2 km of the nearest hospital.4While the attendance rates at accident and emergency departments from the two practices were significantly different, the outcomes, in terms of the proportions of patients admitted and referred on to outpatients, were similar (table). This suggests that case mix and severity vary between apparently similar practice populations.
If practice based budgets are to be based on an equitable allocation of scarce resources it is important to develop robust markers of variations in case mix among practices, which can contribute to the debate on resource allocation in primary care.
Distance from department and deprivation are both important in explaining variations in rates
- John Campbell, Senior lecturer.
EDITOR—Carlisle et al's paper is an important contribution to the literature on accident and emergency workload and socioeconomic deprivation.1 I have previously examined determinants of the use of services at the sole accident and emergency department in West Lothian district, Scotland (population 145 000).2I have reanalysed the data to examine, for all 26 local practices, the contributions of socioeconomic deprivation and proximity to the hospital to variations in annual rates of self referral to the department.
The straight line distance between the practice and the accident and emergency department was calculated with Pythagoras's theorem applied to the relevant grid references. The Carstairs deprivation score was allocated to practices by using the postcode sector for the practice address.3Spearman correlation coefficients were calculated between rates of attendance at the accident and emergency department, the deprivation measure for the practice, and the distance between the practice and the accident and emergency department. Stepwise linear regression analysis was used to examine further the relations between these variables.
The mean (SD) annual rate of self referral to the accident and emergency department for the 26 practices was 127.4 (45.5) attendances/1000 registered patients/year (median 132.7; range 30.0-212.2). There were significant correlations between rates of attendance at the department and the Carstairs deprivation score for the practice (Spearman r=0.584, P<0.01) and the distance between the practice and the department (r=−0.486, P<0.05). Distance to the department β=−0.5, r2=23%) and the Carstairs deprivation score β=0.51, r2=21%) accounted for 44% of the variation in attendance at the department between practices.
The recent steady rise in rates of attendance at accident and emergency departments requires explanation.4 My previous study reported only distance as an independent predictor of rates of attendance at such departments after the accessibility of the general practitioner had been taken into consideration.2Carlisle et al studied out of hours activity; this work here relates to all attendances at an accident and emergency department by patients from practices in West Lothian. While Carlisle et al suggest that deprivation rather than proximity is the more important influence on attendance, the results presented here suggest that both distance and deprivation are of roughly equal importance in explaining variations between practices in self referral to an accident and emergency department. Studies of accident and emergency workload need to take account of proximity and deprivation as potentially important variables influencing utilisation of services.