Houston S, Dawson K, Butler S. Fatigue reporting among aircrew: incidence rate and primary causes. Aviat Space Environ Med 2012; 83:800–4. Introduction: In this study we describe our experience of voluntary fatigue reporting among pilots and cabin crew. Method: This was a prospective study to determine the crude incidence rate and primary cause of Fatigue Report Form submission among cabin crew and pilots within one airline. All crew duties had already undergone scrutiny at the ‘roster build’ stage to ensure compliance with fatigue control measures. Reports were investigated by the airline’s medical officer to determine the primary cause of fatigue and then allocated to one of five categories. The frequency and proportion of reports within each category was determined. Results: The crude incidence rate of fatigue report submission was 103 and 68 cases per 1000 persons per year for pilots and cabin crew, respectively. The primary cause for 27% of reports was attributed to the rostered duty pattern. Of the reports, 24% were primarily caused by roster disruption, 17% by problems with layover accommodation or transport, 23% by a domestic issue, and 9% had no obvious cause or were deemed invalid. A subanalysis of the ‘domestic’ category revealed that half had a primary cause attributable to commuting to or from the workplace. Conclusion: The number and trend of reports received per month can be used to detect otherwise unknown fatigue hazards and identify where improvements can be made. Fatigue reports allow individual crewmembers to give vital feedback on ‘whole-of-life’ fatigue risks, both inside and outside the workplace.