Sense of Life Worth Living (Ikigai) and Mortality in Japan: Ohsaki Study
[THE COMPLETE PUBLISHED ARTICLE READ IN FULL AT SOURCE, including both hazard-ratio tables, Table 1 of baseline characteristics, the covariate list, the stratified analyses in Table 3, the limitations and the reference list, from the PDF at se-realiser.com] Sone, T., Nakaya, N., Ohmori, K., Shimazu, T., Higashiguchi, M., Kakizaki, M., Kikuchi, N., Kuriyama, S., & Tsuji, I. (2008). 'Sense of Life Worth Living (Ikigai) and Mortality in Japan: Ohsaki Study.' Psychosomatic Medicine, 70(6), 709-715. doi:10.1097/PSY.0b013e31817e7e64. Sone is first author, confirmed on the article's own byline, Division of Epidemiology, Department of Public Health and Forensic Medicine, Tohoku University Graduate School of Medicine, Sendai. THE ANCHOR COHORT AND THE MEASUREMENT FINDING. DESIGN: a 93-item self-administered questionnaire distributed October to December 1994 to all National Health Insurance beneficiaries aged 40 to 79 in the catchment of the Ohsaki Public Health Center, fourteen municipalities in Miyagi Prefecture, n = 54,996; response rate 94.6 per cent, n = 52,029; 811 excluded for death or withdrawal before 1 January 1995, leaving 51,218; then 2,939 excluded for not answering the ikigai item and 4,888 for a history of cancer, myocardial infarction or stroke; FINAL ANALYTIC SAMPLE 43,391, being 20,625 men and 22,766 women. Follow-up 1 January 1995 to 31 December 2001, 269,989 person-years, 3,048 deaths (7.0 per cent) and 5,187 lost to follow-up (12.0 per cent). Deaths confirmed from death certificates coded to ICD-10; none of the subjects died of unknown causes. THE MEASURE: ikigai was assessed from the response to a single question, whether the subject had ikigai in their life, with three answer options: yes, uncertain or no. DISTRIBUTION: 25,596 yes (59.0 per cent), 15,782 uncertain (36.4 per cent), 2,013 no (4.6 per cent). RESULTS, reference category 'yes', fully adjusted hazard ratio for 'no' with 95 per cent CI, with the age-and-sex-adjusted figure in brackets to show how much work the confounders do: all-cause 1.5 (1.3-1.7) [2.5, 2.2-2.9]; cancer 1.3 (1.0-1.6), p = .061, NOT SIGNIFICANT [1.5, 1.2-2.0]; cardiovascular disease 1.6 (1.3-2.0) [3.0, 2.5-3.7]; stroke 2.1 (1.6-2.9) [3.6, 2.7-4.8]; ischaemic heart disease 0.9 (0.5-1.7), NOT SIGNIFICANT [1.9, 1.1-3.3]; pneumonia 1.8 (1.2-2.7) [4.0, 2.7-5.9]; external causes 1.9 (1.1-3.3) [3.0, 1.8-4.9]; suicide 2.0 (0.9-4.4), p = .11, NOT SIGNIFICANT [2.7, 1.3-5.7]. For 'uncertain', all-cause 1.1 (1.0-1.2). ADJUSTMENT SET: age as a continuous variable, sex, marital status, education, job, self-rated health, perceived mental stress, bodily pain, physical function, body mass index, smoking status, alcohol consumption, time spent walking, sleep duration, and histories of hypertension, diabetes mellitus, kidney disease, liver disease, gastric or duodenal ulcer, arthritis and osteoporosis. ROBUSTNESS: excluding the 644 all-cause deaths of the first two years left all-cause at 1.4 (1.2-1.6) and cardiovascular at 1.6 (1.2-2.0), BUT THE PNEUMONIA ASSOCIATION DISAPPEARED to 1.3 (0.8-2.2); stratified analyses found no significant effect modification by age, sex, marital status, education, employment, self-rated health, perceived mental stress, bodily pain or physical function. LIMITATIONS IN THE AUTHORS' OWN LIST: no information on prevalence of mental illness such as depression; no information on whether ikigai changed during follow-up; and the 2,939 non-responders to the ikigai item were older and far less healthy, which they read as a reason the association 'could have been underestimated'. MECHANISM: the paper states flatly that there have been no reports on the reasons for the increase in cardiovascular mortality in subjects lacking a sense of ikigai, and the candidate pathways it offers are borrowed from other literatures. THE PAPER IS ALSO THE BEST ROUTE TO THE WORD'S ORDINARY MEANING: its introduction cites the Japanese dictionary and gives the word in everyday use, for example a hobby or raising children as what makes life worth living. All estimates are observational and the exposure is one self-reported item answered once in 1994.
[THE COMPLETE PUBLISHED ARTICLE READ IN FULL AT SOURCE, including both hazard-ratio tables, Table 1 of baseline characteristics, the covariate list, the stratified analyses in Table 3, the limitations and the reference list, from the PDF at se-realiser.com] Sone, T., Nakaya, N., Ohmori, K., Shimazu, T., Higashiguchi, M., Kakizaki, M., Kikuchi, N., Kuriyama, S., & Tsuji, I. (2008). 'Sense of Life Worth Living (Ikigai) and Mortality in Japan: Ohsaki Study.' Psychosomatic Medicine, 70(6), 709-715. doi:10.1097/PSY.0b013e31817e7e64. Sone is first author, confirmed on the article's own byline, Division of Epidemiology, Department of Public Health and Forensic Medicine, Tohoku University Graduate School of Medicine, Sendai. THE ANCHOR COHORT AND THE MEASUREMENT FINDING. DESIGN: a 93-item self-administered questionnaire distributed October to December 1994 to all National Health Insurance beneficiaries aged 40 to 79 in the catchment of the Ohsaki Public Health Center, fourteen municipalities in Miyagi Prefecture, n = 54,996; response rate 94.6 per cent, n = 52,029; 811 excluded for death or withdrawal before 1 January 1995, leaving 51,218; then 2,939 excluded for not answering the ikigai item and 4,888 for a history of cancer, myocardial infarction or stroke; FINAL ANALYTIC SAMPLE 43,391, being 20,625 men and 22,766 women. Follow-up 1 January 1995 to 31 December 2001, 269,989 person-years, 3,048 deaths (7.0 per cent) and 5,187 lost to follow-up (12.0 per cent). Deaths confirmed from death certificates coded to ICD-10; none of the subjects died of unknown causes. THE MEASURE: ikigai was assessed from the response to a single question, whether the subject had ikigai in their life, with three answer options: yes, uncertain or no. DISTRIBUTION: 25,596 yes (59.0 per cent), 15,782 uncertain (36.4 per cent), 2,013 no (4.6 per cent). RESULTS, reference category 'yes', fully adjusted hazard ratio for 'no' with 95 per cent CI, with the age-and-sex-adjusted figure in brackets to show how much work the confounders do: all-cause 1.5 (1.3-1.7) [2.5, 2.2-2.9]; cancer 1.3 (1.0-1.6), p = .061, NOT SIGNIFICANT [1.5, 1.2-2.0]; cardiovascular disease 1.6 (1.3-2.0) [3.0, 2.5-3.7]; stroke 2.1 (1.6-2.9) [3.6, 2.7-4.8]; ischaemic heart disease 0.9 (0.5-1.7), NOT SIGNIFICANT [1.9, 1.1-3.3]; pneumonia 1.8 (1.2-2.7) [4.0, 2.7-5.9]; external causes 1.9 (1.1-3.3) [3.0, 1.8-4.9]; suicide 2.0 (0.9-4.4), p = .11, NOT SIGNIFICANT [2.7, 1.3-5.7]. For 'uncertain', all-cause 1.1 (1.0-1.2). ADJUSTMENT SET: age as a continuous variable, sex, marital status, education, job, self-rated health, perceived mental stress, bodily pain, physical function, body mass index, smoking status, alcohol consumption, time spent walking, sleep duration, and histories of hypertension, diabetes mellitus, kidney disease, liver disease, gastric or duodenal ulcer, arthritis and osteoporosis. ROBUSTNESS: excluding the 644 all-cause deaths of the first two years left all-cause at 1.4 (1.2-1.6) and cardiovascular at 1.6 (1.2-2.0), BUT THE PNEUMONIA ASSOCIATION DISAPPEARED to 1.3 (0.8-2.2); stratified analyses found no significant effect modification by age, sex, marital status, education, employment, self-rated health, perceived mental stress, bodily pain or physical function. LIMITATIONS IN THE AUTHORS' OWN LIST: no information on prevalence of mental illness such as depression; no information on whether ikigai changed during follow-up; and the 2,939 non-responders to the ikigai item were older and far less healthy, which they read as a reason the association 'could have been underestimated'. MECHANISM: the paper states flatly that there have been no reports on the reasons for the increase in cardiovascular mortality in subjects lacking a sense of ikigai, and the candidate pathways it offers are borrowed from other literatures. THE PAPER IS ALSO THE BEST ROUTE TO THE WORD'S ORDINARY MEANING: its introduction cites the Japanese dictionary and gives the word in everyday use, for example a hobby or raising children as what makes life worth living. All estimates are observational and the exposure is one self-reported item answered once in 1994.
Written from the tHE COMPLETE PUBLISHED ARTICLE READ IN FULL AT SOURCE, including both hazard-ratio tables, Table 1 of baseline characteristics, the covariate list, the stratified analyses in Table 3, the limitations and the reference list, from the PDF at se-realiser.com.
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Sone, T., Nakaya, N., Ohmori, K., Shimazu, T., Higashiguchi, M., Kakizaki, M., Kikuchi, N., Kuriyama, S., & Tsuji, I. (2008). Sense of Life Worth Living (Ikigai) and Mortality in Japan: Ohsaki Study. Psychosomatic Medicine, 70(6), 709-715. doi:10.1097/PSY.0b013e31817e7e64