Shift-dependent differences in self-reporting of health symptoms among shiftworkers

The health measures within the Standard Shiftwork Index (SSI) do not require responses to be anchored to a specific time frame or shift context. Thus, the validity and sensitivity of these measures, as indicators of the relative impact of different types of shifts (or shift-schedules), are questionable. This study examined self-reports of gastrointestinal and cardiovascular symptoms. Modified versions of the SSI health measures were administered to a sample of 28 rotating shiftworkers to obtain: (1) reports of general, non-shift-specific symptoms; (2) reports of symptoms generally experienced when on the day and night shift (shift-dependent reports); and (3) reports of symptoms obtained immediately following completion of a set of day and night shifts (shift-cycle-dependent reports). Symptom frequencies were reported differentially for day and night shift. General, non-shift-specific reports represented an approximate average of these reports. Furthermore, self-reports of symptoms varied depending on when in the shift-cycle they were reported; night shift symptoms were greater than those on day shift. No differences were detected between retrospective reports of shift-dependent symptoms and reports made immediately following completion of a set of shifts. The implications of the findings were discussed in relation to the formatting of the SSI health measures. Relevance to industry This study is relevant to researchers and managers who require accurate measurement tools to assess and/or develop work schedules that minimize the impact of shiftwork on the health of workers.