Shift work effects on serial PEF measurements for occupational asthma.

Area of Science:

• Occupational Medicine
• Pulmonary Function Testing
• Workplace Health

Background:

• Diurnal variation (DV) influences lung function, often attributed to sleep rather than time of day.
• Serial peak expiratory flow (PEF) measurements are standard for diagnosing occupational asthma (OA), but shift work may confound results.

Purpose of the Study:

• To investigate the impact of shift work on PEF measurements used in OA diagnosis.
• To evaluate diagnostic accuracy metrics across different shift patterns.

Main Methods:

• Analysis of PEF records from workers with varying shift patterns (≥ 4 days/shift).
• Occupational asthma diagnosis based on Oasys-2 score (≥ 2.51 for OA, <2.51 for non-OA).
• Calculation of mean Area Between Curves (ABC) score, PEF DV, and cross-shift PEF changes per shift.

Main Results:

• In the OA group, PEF declined more during afternoon and night shifts compared to day shifts.
• The ABC score showed reduced values on night and afternoon shifts in the OA group.
• Among non-OA individuals, cross-shift PEF increased significantly on day shifts versus other shifts.
• Diagnostic sensitivity for ABC score and DV was similar across shifts, but DV specificity was lower (39% vs. 98% for ABC).

Conclusions:

• Shift type demonstrates minor differences in PEF responses between work and rest periods.
• The ABC score maintains high sensitivity and specificity for OA diagnosis across all shift types.
• Diurnal variation (DV) exhibits lower specificity for OA diagnosis when confounded by shift work.