† Carol M. Ashton*, † Deborah J. Del Junco*, † Julianne Souchek*, † Nelda P. Wray*, † Carol L. Mansyur*

To help resolve the current controversy over the validity of early readmission as an indicator of the quality of care, the authors critically reviewed the literature using meta-analysis to derive summary estimates of effect and evaluate inter-study heterogeneity. The authors selected reports meeting five criteria: (1) presentation of new data on medical-surgical hospitalization of adults; (2) measurement of outcome as a person-specific readmission; (3) readmission within < or = 31 days; (4) examination of some aspect of the process of inpatient care; (5) inclusion of a comparison group. One meta-analysis examined 13 comparisons of readmission rates after substandard versus normative care, another examined 9 comparisons of readmission rates after normative versus exceptional care, and the third examined all 22 comparisons together. Two authors applied inclusion criteria and extracted data on methods and findings. Two others classified studies on 11 methodological variables for the heterogeneity evaluation. The summary odds ratio for readmission after substandard care was 1.24 (0.99-1.57) relative to normative care; for readmission after normative care the summary odds ratio was 1.45 (0.90-2.33) relative to exceptional care. The individual odds ratios varied significantly (chi2, 21 df = 50.34, P = 0.0003). Most of the variance in study odds ratios could be explained by whether the study focused on the quality of patient care or the qualifications of patient care providers. The summary odds ratio for the 16 homogeneous comparisons focusing on the quality of patient care was 1.55 (1.25-1.92). Early readmission is significantly associated with the process of inpatient care. The risk of early readmission is increased by 55% when care is of relatively low quality, that is, substandard or normative instead of normative or exceptional.