[{"data":1,"prerenderedAt":-1},["ShallowReactive",2],{"health-study-detail:100658307":3},{"organization":4,"outcomesModule":7,"designInfo":68,"detailedDescription":75,"studyPopulation":67,"armGroups":76,"interventions":87,"overallOfficials":67,"centralContacts":92,"locations":98,"responsibleParty":126,"collaborators":128,"id":131,"slug":132,"hasResults":133,"nctId":134,"briefTitle":135,"officialTitle":136,"acronym":137,"eligibilityCriteria":138,"healthyVolunteers":139,"sex":140,"minAge":141,"maxAge":67,"enrollmentInfo":142,"targetDuration":67,"studyType":145,"phases":146,"briefSummary":148,"conditions":149,"keywords":152,"overallStatus":160,"whyStopped":67,"lastUpdateSubmitDate":161,"lastUpdatePostDateStruct":162,"startDateStruct":165,"completionDateStruct":166,"leadSponsor":168,"locationsCount":169},{"fullName":5,"class":6},"Finnish Institute of Occupational Health","OTHER",{"primaryOutcomes":8,"secondaryOutcomes":25,"otherOutcomes":67},[9,13,16,19,22],{"measure":10,"description":11,"timeFrame":12},"Sickness Absence Rate","Percentage of working time lost due to sickness absence, derived from administrative, payroll-based employer records. No medical or diagnostic information will be collected.","From enrollment to the end of treatment at 66 weeks.",{"measure":14,"description":15,"timeFrame":12},"Employee Turnover","Termination of employment during the follow-up period, derived from employment records.",{"measure":17,"description":18,"timeFrame":12},"Retention of Employees Performing Night Work","Proportion of employees performing regular night work who remain employed and performing night shifts during the follow-up period.",{"measure":20,"description":21,"timeFrame":12},"Total Weekly Working Hours","Average number of paid working hours per week, derived from administrative, payroll-based working-hour records.",{"measure":23,"description":24,"timeFrame":12},"Number of Morning, Day, Evening, and Night Shifts","Number or rate of shifts worked during each scheduling period, categorized according to shift type (morning, day, evening, and night) using employer payroll-based working-hour records.",[26,29,32,35,38,41,44,47,50,53,56,60,63],{"measure":27,"description":28,"timeFrame":12},"Number of Sickness Absence Episodes","Total number of sickness absence episodes recorded in administrative payroll-based employer records.",{"measure":30,"description":31,"timeFrame":12},"Total Sickness Absence Days from Short Episodes (1-5 days) of Sickness Absence","Total number of sickness absence days from short episodes of sickness absence recorded in administrative payroll-based employer records.",{"measure":33,"description":34,"timeFrame":12},"Short-Term Sickness Absence Episodes (1-5 Days)","Number of sickness absence episodes lasting 1-5 consecutive calendar days.",{"measure":36,"description":37,"timeFrame":12},"Number of Consecutive Shifts","Number of instances in which employees work consecutive shifts without a day off, derived from administrative, payroll-based working-hour records.",{"measure":39,"description":40,"timeFrame":12},"Overtime Hours","Total number of overtime hours worked during each scheduling period, derived from administrative, payroll-based working-hour records.",{"measure":42,"description":43,"timeFrame":12},"Recovery Periods Between Shifts","Duration of rest periods between consecutive shifts, calculated from shift start and end times recorded in payroll-based working-hour data.",{"measure":45,"description":46,"timeFrame":12},"Number of Quick Returns (\u003C11 Hours Between Shifts)","Number of occurrences in which the interval between the end of one shift and the start of the next shift is less than 11 hours, derived from payroll-based working-hour records.",{"measure":48,"description":49,"timeFrame":12},"Weekend Work","Number of shifts worked during weekends, derived from administrative, payroll-based working-hour records.",{"measure":51,"description":52,"timeFrame":12},"Perceived Effects on Recovery","Employees', supervisors', shift planners', and managers' perceptions of the effects of the working-hour reduction on recovery from work, assessed using semi-structured interviews for focus group including employees, shift planners and management.",{"measure":54,"description":55,"timeFrame":12},"Perceived Effects on Work-Life Balance","Participants' perceptions of the effects of the working-hour reduction on work-life balance, assessed using semi-structured interviews for focus group including employees, shift planners and management.",{"measure":57,"description":58,"timeFrame":59},"Perceived Effects on Workload and Staffing","Participants' perceptions of the effects of the working-hour reduction on workload, staffing adequacy, and continuity of services, assessed using semi-structured interviews for focus group including employees, shift planners and management.","From enrollment to the end of study at 66 weeks.",{"measure":61,"description":62,"timeFrame":59},"Implementation Process","Experiences regarding the organization and implementation of the working-hour reduction, including facilitating factors and implementation challenges, assessed using semi-structured interviews for focus group including employees, shift planners and management.",{"measure":64,"description":65,"timeFrame":66},"Perceived Advantages and Disadvantages of the Intervention","Participants' views regarding positive consequences, unintended effects, challenges, and recommendations for future implementation of reduced working hours, assessed using semi-structured interviews for focus group including employees, shift planners and management.","From enrollment to the end of study at 66 weeks",null,{"allocation":69,"interventionModel":70,"interventionModelDescription":71,"primaryPurpose":72,"observationalModel":67,"timePerspective":67,"maskingInfo":73},"NON_RANDOMIZED","PARALLEL","Participants are effectively in one of two concurrent conditions:\n\n1. Reduced working hours (36 h)\n2. Standard working hours (38 h 15 min)","PREVENTION",{"masking":74,"maskingDescription":67,"whoMasked":67},"NONE","Introduction Night work is associated with increased fatigue, impaired recovery, sickness absence, and difficulties in maintaining long-term work ability (Kecklund \\& Axelsson, 2016; Krutova et al., 2022). In addition, night work has been classified as probably carcinogenic to humans (IARC Working Group on the Identification of Carcinogenic Hazards to Humans, 2020). One potential strategy for reducing the burden associated with night work is to decrease total working hours while maintaining service quality and workforce availability. Although organizations have experimented with reduced working hours (Hanbury et al., 2023; Neubert et al., 2022; Voglino et al., 2022) detailed examination of large-scale workplace interventions for the effects of working-hour reduction among night workers using administrative, payroll-based working-hour data remains very limited.\n\nThe present study evaluates a reduction in weekly working hours from 38 hours 15 minutes to 36 hours among employees working night shifts in Finnish wellbeing services counties using administrative, payroll-based, employer-owned working-hour data (see e.g., Härmä et al., 2015; Härmä et al., 2025; Ropponen et al., 2024).\n\nIntervention The natural experiment of working hour reduction, later referred to as the intervention, consists of reducing contractual weekly working hours from 38 hours 15 minutes to 36 hours among employees working regular night shifts. At the earliest, the implementation will begin in late September 2026 in three Finnish wellbeing services counties. Due to organizational decision-making and operational requirements, the intervention will be introduced at different time points (from September 2026 to early 2027) in different counties in a non-randomized manner using a staggered implementation design.\n\nThe participating organizations will modify shift schedules and staffing arrangements to accommodate the reduced working hours while ensuring continuity of services among those work units that have voluntarily decided to participate in the intervention. Control units consisting of matched work units will continue operating under the standard working-hour arrangement of 38 hours 15 minutes per week.\n\nData Sources The study will primarily utilize administrative, payroll-based, employer-owned working-hour data (see e.g., (Harma et al., 2015; Härmä et al., 2025; Ropponen et al., 2024)). The data will include day-to-day information on shift start and end times, shift duration, number of morning, day, evening and night shifts, number of consecutive shifts, weekend work, overtime hours, sickness absence (without any health or medical information), other absences and absence types (such as childcare or education), job title, work contracts and employment start and end dates. The data also includes information on organizational structure, including work units. The data will be processed both at the individual- and work unit-level as well as annual and scheduling-period summary measures.\n\nStudy Design The study will employ a non-randomized quasi-experimental design. The impact of the reduced working-hours (i.e., intervention) will be evaluated by comparing (1) changes before and during the implementation within intervention units, (2) changes between the intervention and the control units, and (3) changes across wellbeing services counties with different implementation schedules using a difference-in-differences framework (see, e.g., Turunen et al., 2020 and Turunen et al., 2025 for a similar approach in evaluating a participatory scheduling program implementation and national legislative change reducing the occurrence of quick returns, defined as rest periods of less than 11 hours between shifts, respectively).\n\nThe staggered introduction of the intervention across the three wellbeing services counties allows the use of longitudinal and difference-in-differences approaches to strengthen causal inference.\n\nBaseline data will be collected from employer records before and during the implementation. Employer records will be available from the beginning of 2023 through the end of 2027, providing approximately 47 months of pre-intervention data and at least 15 months during the intervention, depending on the intervention start date in each county.",[77,83],{"label":78,"type":79,"description":80,"interventionNames":81},"Reduced working hours (36 h)","EXPERIMENTAL","Reduced working hours (36 h) for those who regularly conduct night shift work.",[82],"Other: Reduced Working Hours (from 38h15minutes to 36h)",{"label":84,"type":85,"description":86,"interventionNames":67},"Standard working hours (38 h 15 min)","NO_INTERVENTION","Standard working hours (38 h 15 min) for those whose organisation or unit did not choose to participate in the trial.",[88],{"type":6,"name":89,"description":90,"armGroupLabels":91,"otherNames":67},"Reduced Working Hours (from 38h15minutes to 36h)","Reduced Working Hours (from 38h15minutes to 36h) for those conducting night shift work regularly",[78],[93],{"name":94,"role":95,"phone":96,"phoneExt":67,"email":97},"Annina Ropponen, Professor","CONTACT","+358304742012","annina.ropponen@ttl.fi",[99,110,118],{"facility":100,"status":67,"city":101,"state":67,"zip":67,"country":102,"countryCode":103,"cosmosGeoPoint":104,"geoPoint":109,"contacts":67},"Kainuun hyvinvointialue","Kajaani","Finland","FI",{"type":105,"coordinates":106},"Point",[107,108],27.72846,64.22728,{"lat":108,"lon":107},{"facility":111,"status":67,"city":112,"state":67,"zip":67,"country":102,"countryCode":103,"cosmosGeoPoint":113,"geoPoint":117,"contacts":67},"Päijät-Hämeen hyvinvointialue","Lahti",{"type":105,"coordinates":114},[115,116],25.66151,60.98267,{"lat":116,"lon":115},{"facility":119,"status":67,"city":120,"state":67,"zip":67,"country":102,"countryCode":103,"cosmosGeoPoint":121,"geoPoint":125,"contacts":67},"Pohjois-Pohjanmaan hyvinvointialue","Oulu",{"type":105,"coordinates":122},[123,124],25.46816,65.01236,{"lat":124,"lon":123},{"type":127,"investigatorFullName":67,"investigatorTitle":67,"investigatorAffiliation":67,"oldNameTitle":67,"oldOrganization":67},"SPONSOR",[129],{"name":130,"class":6},"Finnish Work Environment Fund","100658307","night-work-hours-reduction-trial-100658307",false,"NCT07848607","Night Work Hours Reduction Trial","Trial of Reduced Working Hours Among Regular Night Shift Workers in Public Health and Social Care","WHRedu","Inclusion Criteria:\n\nEmployment in one of the participating Finnish wellbeing services counties. Employees working in work units participating in the study. For the primary analyses, employees who work regular night shifts. Employees with available administrative, payroll-based working-hour and employment records.\n\nExclusion Criteria:\n\nExclusive day workers. Employees performing shift work that does not include night shifts. For the primary analyses, employees not engaged in regular night work.\n\nEmployees not performing regular night work may be included in secondary analyses evaluating workplace-level spillover effects.",true,"ALL","18 Years",{"count":143,"type":144},200,"ESTIMATED","INTERVENTIONAL",[147],"NA","The primary aim of this study is to investigate the effects of reducing weekly working hours among employees working night shifts regularly from 38 hours 15 minutes to 36 hours on payroll-based, objective working-hour characteristics, sickness absence, and workforce retention. The secondary aim is to investigate experiences of promoting and hindering factors related to the working-hour reduction, its implementation process, and perceived benefits and challenges.\n\nThe working-hour reduction will be implemented in three Finnish wellbeing services counties with different starting dates, the first being in late September 2026 and the latest in early 2027. The working-hour reduction has been agreed upon by the parties to the collective agreement for Finnish public social and health care. Thus, intervention is a so-called natural experiment in a real-life setting.\n\nThe effects of the intervention will be evaluated using a quasi-experimental design with staggered, non-randomized implementation across participating counties. Administrative, payroll-based, employer-owned working-hour data, including records of sickness absences without any medical or health information and other absences (including unpaid, education, and childcare), will be used to compare changes before and during the intervention among work units participating in the working-hour reduction. The investigation will also utilize matched work units that do not participate in the reduction (i.e., intervention) as control units (i.e., continuing standard working-hour arrangements).",[150,151],"Night Shift Work","Sickness Absence",[153,154,155,150,156,151,157,158,159],"Working Time Reduction","Reduced Working Hours","Night Work","Healthcare Workers","Employee turnover","Payroll-Based Working Hour Data","Quasi-experimental Study","NOT_YET_RECRUITING","2026-09-23",{"date":163,"type":164},"2026-09-30","ACTUAL",{"date":163,"type":144},{"date":167,"type":144},"2028-04-01",{"name":5,"class":6},3]