Nuclear medicine studies of aging--I. Procedure utilization in the oldest old

Analyses of procedure utilization are of importance if accurate projections are to be made of local and national needs as the population ages. Nuclear Medicine records of a general hospital were analyzed for 1986, to determine utilization patterns in the oldest old (age 85 years and greater) as compared with younger patients. The most elderly comprised 1.3% of the population of this state, but "consumed" 3.9% of the studies carried out in Nuclear Medicine (or a rate 3 times greater than expected). The average number of procedures/patient during the year was 1.56 in the oldest old vs 1.57 in younger individuals. The sex ratio of procedure utilization was 65% female (slightly lower than state wide national estimates of the female portion of the population). A far lower percentage of studies were performed as outpatients in the oldest old (12.2%) than in the younger population (44.9%); contributing factors were discussed. Of the procedures, several had the same percentage utilization in the oldest old and younger groups (gated cardiac blood pool, liver plus hepatobiliary, and radiogallium imaging). Bone scans were slightly less common in the very elderly. However, thyroid studies and radiothallium cardiac imaging were performed significantly less frequently in the more elderly. Procedures carried out more frequently in the very elderly were gastrointestinal bleeding examinations and lung imaging. Possible reasons for this were pointed out.