Choledocholithiasis causing obstructive jaundice 52 years after cholecystectomy.

good test-retest reliability. We used an interview format because it offers the advantage of minimizing missing and inappropriate responses.' In our study, 18 of 19 residents were able to successfully complete the instrument, allowing calculation of a global score. This is an essential part of the PSQI because it is this global score that differentiates good from poor sleepers. Because all of our subjects were cognitively intact, our results cannot be generalized to all nursing home residents. Even though the interview-administered PSQI does not provide a specific diagnosis, its discriminative ability makes it an attractive research instrument as well as a clinical screening tool to identify older subjects who have poor sleep quality and need further evaluation. Clinicians and investigators might consider expanding its use to older people in other settings. It could be useful, for example, in outpatient clinics and assisted living situations for those subjects who are cognitively intact but too frail to selfadminister a questionnaire.