Do patient experiences on priority aspects of health care predict their global rating of quality of care? A study in five patient groups.

BACKGROUND: Patient-given global ratings are frequently interpreted as summary measures of the patient perspective, with limited understanding of what these ratings summarize. Global ratings may be determined by patient experiences on priority aspects of care.
OBJECTIVES: (i) identify patient priorities regarding elements of care for breast cancer, hip- or knee surgery, cataract surgery, rheumatoid arthritis and diabetes, (ii) establish whether experiences regarding priorities are associated with patient-given global ratings, and (iii) determine whether patient experiences regarding priorities are better predictors of global ratings than experiences concerning less important aspects of care. SETTING AND PARTICIPANTS: Data collected for the development of five consumer quality index surveys - disease-specific questionnaires that capture patient experiences and priorities - were used.
RESULTS: Priorities varied: breast cancer patients for example, prioritized rapid access to care and diagnostics, while diabetics favoured dignity and appropriate frequency of tests. Experiences regarding priorities were inconsistently related to global ratings of care. Regression analyses indicated that demographics explain 2.4-8.4% of the variance in global rating. Introducing patient experiences regarding priorities increased the variance explained to 21.1-35.1%; models with less important aspects of care explained 11.8-23.2%.
CONCLUSIONS: Some experiences regarding priorities are strongly related to the global rating while others are poorly related. Global ratings are marginally dependent on demographics, and experiences regarding priorities are somewhat better predictors of global rating than experiences regarding less important elements. As it remains to be fully determined what global ratings summarize, caution is warranted when using these ratings as summary measures.