Table 1 Compressed Working Week: prospective cohort studies with a control group

Study	Design and critical appraisal (see criteria in box 3)	Setting and participants	Summary results
Study	Design and critical appraisal (see criteria in box 3)	Setting and participants	↑ = improvement ↓ = worsening ↔ = little change
Barton-Cunningham, 1981, 198234 35	Five-month and six-month follow-upsFinal sample: n = 30 (17 intervention, 13 control)Critical appraisal: 1 4 7 9	Police force, CanadaPolice officers, majority menFive eight-hour shifts, two days off to Four 10-hour shifts, three days off	Sporting activitiesAbsenteeismTime spent on domestic choresTime spent on family mattersTime spent with spouseTime spent socialising with friendsJob satisfaction	↑↔↑↑↑↑↔
Barton-Cunningham, 198936	Unspecified follow-upFinal sample: n = 85 (68 intervention, 17 control)Critical appraisal: 1 7 9 10	Mine, CanadaMine operatives and plant operators, young married males, age<39Five eight-hour shifts, two days off to Four 12-hour shifts, four days off	AbsenceAccidentsSleep problemsTirednessFamily satisfactionSatisfaction with work	↑↑↔↔↔↔
Totterdell & Smith, 199237	Six-month follow-upFinal sample: n = 70 (40 intervention, 30 control)Critical appraisal: 1 2 3 5 7 9 10	Police service, UKPolice officersSeven eight-hour shifts, two days off to Ottawa system (10-hour days and eight-hour nights)	GHQLack of sleepFatigueHeadachesStomach achesSleep durationStressFeeling unwellIrregular mealsSleep qualityInsufficient time for familyInsufficient time for friendsInsufficient time for social lifePersonal life disruptedPlanning social life difficultDomestic arrangements difficultPoor relations with familyNot enough free timeEffective at workFatigue affects work	↑↑↑↑↑↑↑↑↑↔↑↑↑↑↑↑↑↑↑↑
Lowden et al, 199838	10-month follow-up	Chemical plant, Sweden	Easy to fall asleep	↑
	Final sample: n = 46 (32 intervention, 14 control)	Plant operators, mainly men	Rested when wake up	↑
	Critical appraisal: 1 2 4 5 7 9 10	Five eight-hour shifts, three days off to two or three 12-hour shifts, up to five days off	Sleep qualityFatigueSufficient sleepGeneral healthTime for social/family activitiesSatisfaction with hours	↑↔↔↔↑↑
Smith et al, 199839	Six-month follow-up	Police service, UK	Sleep duration (day)	↑†
	Final sample: n = 45 (27 intervention, 18 control)	Police officers, mainly men	Standard Shiftwork Index	↓†
	Critical appraisal: 1 2 4 7 8 9 10	Five or seven eight-hour shifts, two or three days off to site A: flexible starts with four 12-hour shifts, then four days off; or site B: rigid starts with four 12-hour shifts, then four days off	Sleep quality (rest)Standard Shiftwork IndexChronic fatigueStandard Shiftwork IndexPhysical healthStandard Shiftwork IndexGHQ-12WorkloadSocial/domestic interference	↓†↔↔↔↑†↔

Effect sizes have been added to the text where appropriate and the detailed results are available in online table E1.
*There were significant differences between intervention and control groups at baseline.
†Effect disappeared when shift work experience was controlled for.