Validity and reliability of the Patient Centred Assessment Method for patient complexity and relationship with hospital length of stay: a prospective cohort study

OBJECTIVES: Several instruments for evaluating patient complexity have been developed from a biopsychosocial perspective. Although relationships between the results obtained by these instruments and the length of stay in hospital have been examined, many instruments are complicated and not easy to use. The Patient Centred Assessment Method (PCAM) is a candidate for practical use. This study aimed to test the validity and reliability of the PCAM and examine the correlations between length of hospital stay and PCAM scores in a regional secondary care hospital in Japan. DESIGN: Prospective cohort study. PARTICIPANTS AND SETTING: Two hundred and one patients admitted to Ouji Coop Hospital between July 2014 and September 2014. MAIN PREDICTOR: PCAM total score in initial phase of hospital admission. MAIN OUTCOME: Length of stay in hospital. RESULTS: Among 201 patients (Female/Male=98/103) with mean (SD) age of 77.4±11.9 years, the mean PCAM score was 25±7.3 and mean (SD) length of stay in hospital (LOS) 34.1±40.9 days. Using exploratory factor analysis to examine construct validity, PCAM evidently has a two-factor structure, comprising medicine-oriented and patient-oriented complexity. The Spearman rank correlation coefficient for evaluating criterion-based validity between PCAM and INTERMED was 0.90. For reliability, Cronbach’s alpha was 0.85. According to negative binomial regression analyses, PCAM scores are a statistically significant predictor (p<0.001) of LOS after adjusting for age, gender, Mini Nutritional Assessment Short-Form, Charlson Comorbidity Index, serum sodium concentration, total number of medications and whether public assistance was required. In another model, each factor in PCAM was independently correlated with length of stay in hospital after adjustment (medicine-oriented complexity: p=0.001, patient-oriented complexity: p=0.014). CONCLUSION: PCAM is a reliable and valid measurement of patient complexity and PCAM scores have a significant correlation with hospital length of stay.