The development of a routine NHS data-based index of performance in general practice (NHSPPI)

OBJECTIVES: The aim of this study was to compare two different approaches to the measurement of quality in general practice: data derived from routine NHS data sets and results from an index derived from patient-collected data. METHODS: A secondary analysis of existing data sets and a cross-sectional survey were carried out in Lothian, Coventry, Oxfordshire and west London. The subjects comprised randomly selected and consenting practices, and a sample of patients within these practices. A National Health Service Practice Performance Index (NHSPPI) was constructed from 16 routinely available NHS performance indicators. The Consultation Quality Index (CQI) combines the Patient Enablement Instrument (PEI) with a measure of how well the patient knew the doctor, and with observed consultation length. RESULTS: Scores for 12 of the 16 indicators varied significantly across the four regions. Mean practice NHSPPI score overall was 21.6 (SD 4.3), which varied significantly across regions. NHSPPI was predicted by practice list size, weighted deprivation index and proportion of other language patients in the practice, although their effects could not be separated. Overall there was no correlation between NHSPPI and CQI, although the prescribing component of the index was positively correlated to mean consultation length and negatively correlated with how well patients knew their doctors. CONCLUSIONS: Good quality care as assessed by patients on completion of their consultation is independent of good quality care as assessed by best available measures of practice performance. We suggest that the CQI and the NHSPPI are at least as ready for use as other measures of performance in general practice.