In 2006, a sample of 549 hospital employees was drawn from a major hospital in Beijing that had been affected by the 2003 SARS outbreak. Using hospital employee rosters, a stratified random sample was selected for recruitment into the study. The sample was stratified by profession (with 3 profession categories, that is, doctor, nurse, and administrative and [or] other hospital staff), by age group (34 years and younger, 35 to 55, and 56 and older), and, for the doctor and nurse categories, by high or low level of work exposure to SARS. (Doctors and nurses who had worked in units such as SARS wards, fever clinics, the department of infectious diseases, or the emergency room, where contact with SARS patients was frequent and intense, were classified as having had high work exposure.) The oldest age group (aged 56 years and older) was small and treated as a single sampling stratum. There were 11 resulting strata in the sample.
Doctors and nurses with high work exposure to the SARS outbreak were oversampled. Hospital employees aged 35 to 55 years were also oversampled, for reasons related to a second planned study of children whose parents were hospital employees and were exposed to these events. (However, our study focuses only on the hospital employees themselves.) The study’s response rate was 83%. Participants completed a self-report questionnaire. To produce estimates representative of all of the hospital’s staff, the weight for each stratum was generated as a reciprocal of the stratum-specific probability of being included in the study, multiplied by the ratio of sample size to population size. These weights were used in data analyses to obtain unbiased statistics.
This study was carried out in full compliance with the institutional review boards of the New York State Psychiatric Institute and the Beijing University of Chinese Medicine. Written informed consent was obtained from all participants prior to participation in the study.