Objective To explore whether responses to questions in surveys of patients that purport to assess the performance of general practices or doctors reflect differences between practices, doctors, or the patients themselves.
Design Secondary analysis of data from a study of access to general practice, combining data from a survey of patients with information about practice organisation and doctors consulted, and using multilevel modelling at practice, doctor, and patient level.
Setting Nine primary care trusts in England.
Participants 4573 patients who consulted 150 different doctors in 27 practices.
Main outcome measures Overall satisfaction; experience of wait for an appointment; reported access to care; satisfaction with communication skills.
Results The experience based measure of wait for an appointment was more discriminating between practices (practice level accounted for 20.2% (95% confidence interval 9.1% to 31.3%) of variance) than was the overall satisfaction measure (practice level accounted for 4.6% (1.6% to 7.6%) of variance). Only 6.3% (3.8% to 8.9%) of the variance in the doctors’ communication skills measure was due to differences between doctors; 92.4% (88.5% to 96.4%) of the variance occurred at the level of the patient (including differences between patients’ perceptions and random variation). At least 79% of the variance on all measures occurred at the level of the patient, and patients’ age, sex, ethnicity, and housing and employment status explained some of this variation. However, adjustment for patients’ characteristics made very little difference to practices’ scores or the ranking of individual practices.
Conclusions Analyses of surveys of patients should take account of the hierarchical nature of the data by using multilevel models. Measures related to patients’ experience discriminate more effectively between practices than do measures of general satisfaction. Surveys of patients’ satisfaction fail to distinguish effectively between individual doctors because most of the variation in doctors’ reported performance is due to differences between patients and random error rather than differences between doctors. Although patients’ reports of satisfaction and experience are systematically related to patients’ characteristics such as age and sex, the effect of adjusting practices’ scores for the characteristics of their patients is small.