title: Daily home gardening improved survival for older people with mobility limitations: an 11-year follow-up study in Taiwan.
abstract: OBJECTIVE
  To test the hypothesis that gardening is beneficial for survival after taking time-dependent comorbidities, mobility, and depression into account in a longitudinal middle-aged (50-64 years) and older (≥65 years) cohort in Taiwan.
  
  
  METHODS
  The cohort contained 5,058 nationally sampled adults ≥50 years old from the Taiwan Longitudinal Study on Aging (1996-2007). Gardening was defined as growing flowers, gardening, or cultivating potted plants for pleasure with five different frequencies. We calculated hazard ratios for the mortality risks of gardening and adjusted the analysis for socioeconomic status, health behaviors and conditions, depression, mobility limitations, and comorbidities. Survival models also examined time-dependent effects and risks in each stratum contingent upon baseline mobility and depression. Sensitivity analyses used imputation methods for missing values.
  
  
  RESULTS
  Daily home gardening was associated with a high survival rate (hazard ratio: 0.82; 95% confidence interval: 0.71-0.94). The benefits were robust for those with mobility limitations, but without depression at baseline (hazard ratio: 0.64, 95% confidence interval: 0.48-0.87) when adjusted for time-dependent comorbidities, mobility limitations, and depression. Chronic or relapsed depression weakened the protection of gardening. For those without mobility limitations and not depressed at baseline, gardening had no effect. Sensitivity analyses using different imputation methods yielded similar results and corroborated the hypothesis.
  
  
  CONCLUSIONS
  Daily gardening for pleasure was associated with reduced mortality for Taiwanese >50 years old with mobility limitations but without depression.
authors.affiliation: Institute of Allied Health Sciences, College of Medicine, National Cheng Kung University, Tainan; School of Medical Sociology and Social Work, Chung Shan Medical University, Taichung.
authors.forename: Chhian Hūi
authors.initials: CH
authors.lastname: Lêng
authors.affiliation: Department of Public Health, College of Medicine; Department of Occupational and Environmental Medicine; Department of Internal Medicine, National Cheng Kung University Hospital, Tainan, Taiwan.
authors.forename: Jung-Der
authors.initials: JD
authors.lastname: Wang
mesh_terms: D000203:Activities of Daily Living; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging; D003863:Depression / Q000150:complications*; D005260:Female; D005500:Follow-Up Studies; D051639:Gardening; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D051346:Mobility Limitation; D016016:Proportional Hazards Models; D012923:Social Class; D013624:Taiwan
keywords: epidemiology; gardening; leisure activity; mortality; survival