Predictive validity of the P(ra) instrument among older recipients of managed care

OBJECTIVE: to determine the validity of the P(ra) instrument in predicting the use of health-related services by older enrollees in a managed care plan. DESIGN: Cohort study. At baseline, a survey was administered by mail. Responses were entered into the P(ra) formula to estimate each person's probability of using health related services heavily in the future. The subjects' use of services during the following year was monitored through claims submitted to their managed care organization. SETTING: Urban and suburban areas of Southern California. PARTICIPANTS: Persons aged 65 years and older enrolled in a Medicare risk health plan (n = 6802). MEASUREMENTS: Baseline data included demographic, health-related, social, functional, and previous-use-of-service characteristics. Follow up data included the use of and claims for payment for inpatient hospital care, emergency room services, nursing home services, home care, ambulance services, outpatient surgery, and durable medical equipment. RESULTS: High-risk subjects (highest quartile of P(ra) values) incurred hospital admissions and claims that were 2.5 and 2.7 times greater than those of low-risk subjects (lower three quartiles). CONCLUSIONS: The P(ra) formula is recommended for screening older adults enrolled in managed care organizations (as well as for screening those in the fee-for-service environment). It identifies older people who may benefit from interventions designed to avert health crises and the need for expensive care.