Randomized controlled drug trials on very elderly subjects: descriptive and methodological analysis of trials published between 1990 and 2002 and comparison with trials on adults.

BACKGROUND Very elderly subjects (VES; aged 80 years or older) constitute a special population as they frequently present multiple diseases (polypathology). Results from trials on general adult populations therefore cannot be extrapolated to VES. We performed a census of randomized controlled trials (RCT) on VES published between 1990 and 2002, and carried out a descriptive and methodological analysis of these RCT/VES, comparing them with matched RCT on general adult populations (control RCT, RCT/C). METHODS We searched for RCT/VES in two international databases (EMBASE and MEDLINE) and then manually. RCT/C were matched to RCT/VES for disease area and year of publication. The methodological quality of each RCT was assessed with Chalmers' scale. RESULTS We identified 84 RCT/VES, 63 of which were conclusive and 21, inconclusive. Subjects were institutionalized in 48 RCT, and community dwelling in 11 RCT (unspecified in 25 RCT). Efficacy was the main criterion in 75 RCT; tolerance in 9 RCT. Twenty-six RCT were published by geriatrics journals, and 58 by general medical journals. The RCT/VES covered most of the disease areas of geriatrics. The 84 RCT/VES had a mean methodological quality score of 0.578 +/- 0.157. The matched 84 RCT/C had a mean methodological quality score of 0.592 +/- 0.116 (p = .466). The methodological quality score of RCT/VES increased with the number of included subjects (p = .004) and the year of publication (p = .001). CONCLUSIONS The methodological quality of RCT/VES is equivalent to that of RCT in general adult populations. Nevertheless, RCT/VES remain very scarce, and neglect certain diseases. RCT/VES and the inclusion of very elderly subjects in RCT on adults should be strongly encouraged.