In this national study of hospitals, examining the relationship between patient experiences and other measures of hospital quality and safety, there were consistent relationships between patient experiences and technical quality as measured by the measures used in the HQA program, and complication rates as measured by the AHRQ PSIs. Two overall measures of hospital performance, the overall rating of the hospital and willingness to recommend the hospital, had strong relationships with better technical performance in processes of care related to pneumonia, CHF, myocardial infarction, and for surgical care. Better patient experiences in all domains were also associated with lower decubitus ulcer rates. Other complications such as infections due to medical care were strongly related to patient experiences in specific domains, such as whether the hospital environment was clean and quiet, and whether the staff was communicative and responsive.
Another study that examined how patients' experiences of care in hospitals related to HQA process measures found similar relationships (Jha et al. 2008
). Unlike that study, ours examined patients' perceptions of care stratified by hospital service, which allowed more direct comparison of patient experiences and process-based measures of quality among patients being treated by the same groups of physicians and nurses. Other studies of associations between consumer assessments of care and clinical quality have used data from outpatient care and have yielded mixed results (Schneider et al. 2001
; Rao et al. 2006
;). For instance, Medicare health plans with better performance on the CAHPS measures had moderately better performance on several Healthcare Effectiveness Data and Information Set measures (Schneider et al. 2001
). These relationships may have been weaker than those we found in the hospital setting because there can be significant variation across multiple providers of care within a health plan, and individual health plans might have little direct influence on the quality of care provided by clinicians. Conversely, both survey and technical quality measures for hospitals refer to care provided entirely within a single institution, or in the case of our study, within a service line within an institution.
Moreover, compared with the ambulatory care measures, some of the domains of quality measured by HCAHPS might be more directly related to technical quality of care as measured by either PSIs or HQA. For instance, the cleanliness of the hospital environment was strongly related to prevention of hospital-acquired infections, and responsiveness of medical staff was related to better pneumonia care. Such associations are plausible, though it would be a mistake to infer direct causal links. For example, hospital cleanliness as perceived by patients might not directly reduce infections, but both might reflect a focus on prophylaxis that is manifested in ways that are both visible and invisible to patients. Similarly, patient perceptions of the responsiveness of medical staff might reflect the hospital's safety culture and the adequacy and attentiveness of staff, which might also affect adherence to treatment guidelines and prevention of hospital-acquired infection. The nature of these relationships needs further study to better understand the mechanisms that underlie them.
The HCAHPS measures that have been added to the publicly reported measures of the HQA offer consumers, payers, and policy makers a new perspective on hospital quality. They reflect care provided across virtually all conditions cared for on the medical and surgical services rather than for selected conditions such as AMI or pneumonia, which may be especially salient for patients who are not facing urgent admission. Our finding that patient experiences correlate with technical quality of hospitals enhances the importance of these data, and it suggests that the HCAHPS performance might be a useful overall measure that is broadly reflective of hospital quality.
Our findings also have several implications for quality improvement initiatives within hospitals. First, because performance in processes of medical and surgical care was generally related to multiple HCAHPS domains, efforts to improve processes of care may need to reach several hospital areas and involve both doctors and nurses. Second, because the two general HCAHPS measures, overall hospital rating and willingness to recommend the hospital, had the strongest relationships with processes of care, these measures may be useful adjuncts in assessing the effects of some quality improvement initiatives. Finally, some of these relationships may give quality managers a better understanding of how to reduce certain types of safety complications.
Our study has some potentially important limitations. First, we studied a sample of approximately 800 hospitals from the NCBD rather than all general medical and surgical hospitals that report to the HQA. Although we could have used publicly available data from HQA, the NCBD dataset allowed us to examine the experiences of medical and surgical patients separately, a substantial advantage because our preliminary analyses suggested perceptions of care can vary greatly across service lines within a hospital (O'Malley et al. 2005
). Nonetheless, it is possible that the hospitals participating in the NCBD are not representative of hospitals in the United States. Second, each quality measure used has limitations. As mentioned earlier, the HQA measures focus on only a small subset of medical and surgical care. However, the HQA process measures have been widely used as a basis of hospital grading, and CMS and others adopted both of these metrics for payment (Mechanic, Coleman, and Dobson 1998
; Ergin et al. 2004
;). Third, PSIs rely on accurate and complete coding of complications in billing data, and their validity as safety measures has not been well established (Agency for Healthcare Research and Quality 2003
; Zhan and Miller 2003
;). Therefore, our finding that better HCAHPS performance is related to lower incidence of some hospital complications should be interpreted with caution, although the correlations in the expected directions are suggestive of a true relationship across the population of hospitals we studied. Fourth, we performed multiple statistical tests examining associations, which create the potential for false-positive results due to chance. However, we found more relationships than would be expected by chance, and many of these relationships were consistent across specific quality and safety measures. Fifth, severity of patients' illnesses in a hospital service may contribute to perceptions of care and outcomes, but both the HCAHPS measures and the PSIs are adjusted for case mix. Finally, the metrics we used for comparison examine different subsets of patients treated in different time periods. Because our analyses were conducted at the hospital level, we think that it is unlikely that there would be significant changes in one or the other measure set over such a short time period. More closely aligned samples might have demonstrated even higher correlations.
In conclusion, the notable associations between measures of patient experiences of care and technical quality and safety in hospitals suggest that HCAHPS measures are important new measures for hospital care quality, even though further study is necessary to elucidate the implications of these relationships for improving hospital care.