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.