A practical method for monitoring general practice mortality in the UK: findings from a pilot study in a health board of Northern Ireland

Abstract

Background: The Baker report into Dr Harold Shipman's murders recommended monitoring mortality in general practice, but there is currently no practical method available to implement this.

Aim: To monitor mortality rates in response to the Baker report and to use the data to improve quality of care.

Design of study: Prospective mortality monitoring study.

Setting: Eastern Health and Social Services Board, Northern Ireland.

Method: Linked quarterly mortality data from 1994-2001 were compiled for 114 general practices in Eastern Health and Social Services Board in Northern Ireland. Cross-sectional control charts compared crude and adjusted mortality rates across all the practices. Longitudinal control charts analysed quarterly mortality rates over 28 quarters within each practice. Practices were sent their own control charts and invited to feedback workshops. Special cause variation in mortality was investigated as follows: checks on data, case-mix, practice structures, processes of care and finally individual carers.

Results: Age, sex and deprivation adjusted cross-sectional control charts identified 18 practices as showing special cause variation in their mortality (11 high and 7 low). Assignable causes were found for all high special cause practices: large numbers of nursing home patients (six practices), very high levels of deprivation and high morbidity not captured by our case-mix adjustment (five practices). For three of seven low special cause practices, case-mix adjustment underestimated affluence and overestimated morbidity levels. Feedback indicated widespread support for the principle of monitoring, but concerns about the public disclosure of mortality data.

Conclusions: We have successfully developed and piloted a general practice mortality monitoring system with the support and participation of local stakeholders. This used control charts for analysis and followed a scientific strategy for investigating special cause variation.

Figure 1

‘Pyramid’ model of investigation to find a credible cause for high mortality.

Figure 2

Cross-sectional control chart showing age–sex-deprivation adjusted mortality rates for 114 general practices in the Eastern Health and Social Services Board, Northern Ireland (1996–2000).

Figure 3

Longitudinal control chart of general practice A.

Figure 4

Longitudinal control chart of general practice B.

Figure 5

Longitudinal control chart of general practice C.

Figure 6

Longitudinal control chart of general practice D.

Figure 7

Crude death rate in patients aged >75 years at practice D with a least squares line.