Does Laughter Predict Onset of Functional Disability and Mortality Among Older Japanese Adults? The JAGES Prospective Cohort Study.

Kokoro Shirai,Yudai Tamada,Chikae Yamaguchi,Tetsuya Ohira,Masashige Saito,Kenji Takeuchi,Katsunori Kondo

doi:10.2188/jea.je20200051

Abstract

BackgroundWhile laughter is broadly recognized as a good medicine, a potential preventive effect of laughter on disability and death is still being debated. Accordingly, we investigated the association between the frequency of laughter and onset of functional disability and all-cause mortality among the older adults in Japan.MethodsThe data for a 3-year follow-up cohort including 14,233 individuals (50.3% men) aged ≥65 years who could independently perform the activities of daily living and participated in the Japan Gerontological Evaluation Study were analyzed. The participants were classified into four categories according to their frequency of laughter (almost every day, 1–5 days/week, 1–3 days/month, and never or almost never). We estimated the risks of functional disability and all-cause mortality in each category using a Cox proportional hazards model.ResultsDuring follow-up, 605 (4.3%) individuals developed functional disability, identified by new certification for the requirement of Long-Term Care Insurance, and 659 (4.6%) deaths were noted. After adjusting for the potential confounders, the multivariate-adjusted hazard ratio of functional disability increased with a decrease in the frequency of laughter (P for trend = 0.04). The risk of functional disability was 1.42 times higher for individuals who laughed never or almost never than for those who laughed almost every day. No such association was observed with the risk of all-cause mortality (P for trend = 0.39).ConclusionsLow frequency of laughter is associated with increased risks of functional disability. Laughter may be an early predictor of functional disability later on in life.

Highlights

Increasing functional disability, defined as difficulty in performing the activities of daily living, is a significantly important public health concern in rapidly aging societies worldwide.[1]
Identifying the factors for preventing incident functional disability is a critical goal for super-aged societies, including Japan, because age-related functional disability negatively affects an individual’s health status, predicts mortality,[4] and increases the healthcare costs associated with long-term care and hospital services.[5,6]
Study sample This study was based on the cohort data from the Japan Gerontological Evaluation Study (JAGES),[14] which is an ongoing longitudinal study investigating the factors associated with health and well-being in the community-dwelling adults aged ≥65 years who could independently perform the physical and cognitive activities of daily living

Summary

Introduction

Increasing functional disability, defined as difficulty in performing the activities of daily living, is a significantly important public health concern in rapidly aging societies worldwide.[1]. An increasing number of studies have reported the beneficial effects of laughter on several health outcomes among older adults, such as on the cardiovascular functions and diseases and mental health.[7,8,9,10,11] studies assessing the association between laughter and functional disability and mortality, while considering the individuals’ socioeconomic background, have not been reported. The frequency of laughter can vary according to an individual’s socioeconomic status,[12] which is associated with the Address for correspondence. While laughter is broadly recognized as a good medicine, a potential preventive effect of laughter on disability and death is still being debated.

Methods

Results

Conclusion