title: Efficacy of a workplace osteoporosis prevention intervention: a cluster randomized trial.
abstract: Osteoporosis is a debilitating disease. Adequate calcium consumption and physical activity are the two major modifiable risk factors. This paper describes the major outcomes and efficacy of a workplace-based targeted behaviour change intervention to improve the dietary and physical activity behaviours of working women in sedentary occupations in Singapore.
  
  
  
  A cluster-randomized design was used, comparing the efficacy of a tailored intervention to standard care. Workplaces were the units of randomization and intervention. Sixteen workplaces were recruited from a pool of 97, and randomly assigned to intervention and control arms (eight workplaces in each). Women meeting specified inclusion criteria were then recruited to participate. Workplaces in the intervention arm received three participatory workshops and organization-wide educational activities. Workplaces in the control/standard care arm received print resources. Outcome measures were calcium intake (milligrams/day) and physical activity level (duration: minutes/week), measured at baseline, 4 weeks and 6 months post intervention. Adjusted cluster-level analyses were conducted comparing changes in intervention versus control groups, following intention-to-treat principles and CONSORT guidelines.
  
  
  
  Workplaces in the intervention group reported a significantly greater increase in calcium intake and duration of load-bearing moderate to vigorous physical activity (MVPA) compared with the standard care control group. Four weeks after intervention, the difference in adjusted mean calcium intake was 343.2 mg/day (95 % CI = 337.4 to 349.0, p < .0005) and the difference in adjusted mean load-bearing MVPA was 55.6 min/week (95 % CI = 54.5 to 56.6, p < .0005). Six months post intervention, the mean differences attenuated slightly to 290.5 mg/day (95 % CI = 285.3 to 295.7, p < .0005) and 50.9 min/week (95 % CI =49.3 to 52.6, p < .0005) respectively.
  
  
  
  This workplace-based intervention substantially improved calcium intake and load-bearing moderate to vigorous physical activity 6 months after the intervention began.
  
  
  
  Australia New Zealand Clinical Trial Registry ACTRN12616000079448 . Registered 25 January 2016 (retrospectively registered).
authors.affiliation: McCaughey Centre: VicHealth Centre for the Promotion of Mental Health & Community Wellbeing, Melbourne School of Population and Global Health, University of Melbourne, Melbourne, VIC, 3010, Australia. amtan@student.unimelb.edu.au.
authors.forename: Ai May
authors.initials: AM
authors.lastname: Tan
authors.affiliation: McCaughey Centre: VicHealth Centre for the Promotion of Mental Health & Community Wellbeing, Melbourne School of Population and Global Health, University of Melbourne, Melbourne, VIC, 3010, Australia.|Centre for Population Health Research, Building BC, Level 3, School of Health & Social Development, Deakin University, Burwood, VIC, 3125, Australia.
authors.forename: Anthony D
authors.initials: AD
authors.lastname: LaMontagne
authors.affiliation: Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, University of Melbourne, Melbourne, VIC, 3010, Australia.|Cancer Epidemiology Centre, Cancer Council Victoria, Melbourne, 3004, Australia.
authors.forename: Dallas R
authors.initials: DR
authors.lastname: English
authors.affiliation: Melbourne School of Population and Global Health, University of Melbourne, Melbourne, VIC, 3010, Australia.
authors.forename: Peter
authors.initials: P
authors.lastname: Howard
mesh_terms: D000328:Adult; D002136:Calcium, Dietary / Q000008:administration & dosage* / Q000627:therapeutic use; D016000:Cluster Analysis; D004032:Diet; D015444:Exercise; D005247:Feeding Behavior; D005260:Female; D015438:Health Behavior; D006266:Health Education; D006293:Health Promotion / Q000379:methods*; D006801:Humans; D009786:Occupational Health Services; D010024:Osteoporosis / Q000517:prevention & control*; D017063:Outcome Assessment, Health Care; D012846:Singapore; D016896:Treatment Outcome; D016474:Weight-Bearing; D017132:Workplace
chemical_list: D002136:Calcium, Dietary
keywords: Calcium intake; Cluster randomized trial; Osteoporosis prevention; Physical activity; Premenopausal women; Workplace