Hospital versus random digit dialing controls in the elderly. Observations from two case-control studies

Health screening and random recruitment for cognitive aging research

A survey of 197 cognitive aging studies revealed infrequent use of structured health assessments and random recruitment. In this study, a health screening questionnarie developed to identify subjects with medical problems that might impair cognition was administered to 315 adults aged 60 and older who were recruited by random digit dialing. On the basis of self-reported medical problems, 35% of the subjects were excluded. Those excluded were older (p less than .001) and tended to be male but did not differ in education from those who passed the screening. Subjects who passed the screening and decided to participate in a neuropsychological research project were younger (p less than .001), better educated (p less than .001), and more likely to be male (p less than .001) than nonparticipants. These findings suggest that careful assessment, selection, and description of subjects is needed to aid interpretation of cognitive aging research. Further attention to health status is needed to aid interpretation of cognitive aging research. Although random recruitment of the elderly is feasible, obtaining representative samples may require stratification on demographic variables.

Are stressful life events risk factors for herpes zoster?

To determine if psychologically stressful life events are risk factors for herpes zoster, we conducted a case-control study of zoster and self-reported recent negative life events and major changes in spousal relationships. The subjects were 101 healthy community-dwelling cases of zoster and 101 healthy controls matched for age, sex, and race and generated by random digit dialing. The Geriatric Scale of Recent Life Events was administered to case and control subjects, and additional questions were asked regarding the perception of the life event. The results showed that case subjects experienced negative life events significantly more often than subjects in the control groups in the 2 months before zoster onset by analysis of discordant pairs (26 versus 10, odds ratio 2.60, 95% confidence interval [CI] 1.13, 6.27, P = .012), 3 months before (29 versus 11, odds ratio 2.64, 95% CI 1.20, 6.04, P = .007), or 6 months before (35 versus 16, odds ratio 2.00, 95% CI 1.04, 3.93, P = .012). The mean number of total life events was significantly higher in cases at 6 months before zoster (case means = 2.64, control means = 1.82, P = .008), but there were no significant differences at 2, 3, or 12 months before. There were no significant differences between case subjects and control subjects for spousal events, or any given single life event. In conclusion, we found that whereas patients with herpes zoster experienced the same kinds of life events in the year preceding the illness as did control subjects, recent events perceived as stressful were significantly more common among patients with zoster.(ABSTRACT TRUNCATED AT 250 WORDS)