Table 1.
Characteristics of studies included in the meta-analysis
| Author | Study location | Study name | No. of participants | No. of death | Mean Age | Reference | Unmarried status category | Outcomes | Mean/medium follow up (years) | Maximum adjustment available |
|---|---|---|---|---|---|---|---|---|---|---|
| Va et al, 2011 [32] | China | Shanghai Women’s Health Study; Shanghai Men’s Health Study | 127,004 | 4,116 | 53.8 | Married |
Not married Never married Widowed Divorced/separated |
All-cause mortality Cancer mortality CVD mortality CHD mortality Stroke mortality |
NA | Age, income, education, occupation, BMI, WHR, physical activity, smoking, alcohol drinking, ginseng use, HRT, menopause, women only, total energy intake, vegetable and fruit intake, and red meat intake, hypertension, diabetes, baseline CVD, and all other chronic disease |
| Frisch et al, 2013 [33] | Denmark | Civil Registration System | 6,500,000 | 1,709,850 | NA | Married |
Never married Widowed Divorced/separated |
All-cause mortality Cancer mortality CVD mortality |
29 | Age, municipality, population density, educational level, and relative income two years before the actual year |
| Molloy et al, 2009 [35] | Scotland | Scottish Health Survey | 13,880 | 892 | 52.3 | Married |
Never married Widowed Divorced/separated |
All-cause mortality CVD mortality |
7.1 | Age |
| Dupre et al, 2009 [36] | USA | Health and Retirement Study | 8,715 | 1,531 | 55.9 | Married |
Widowed Divorced/separated |
All-cause mortality | 9.4 | Age, ethnicity, region, household size, children, education, occupational status, occupational tenure, wealth, health insurance coverage, smoking, alcohol consumption, physical exercise, BMI, preventive health care, hypertension, diabetes, cancer, lung disease, heart disease, stroke, any ADL limitations, depressive symptoms |
| Scafato et al, 2006 [37] | Italian | Italian Longitudinal Study on Aging | 4,514 | 1,977 | 72.6 | Married | Not married | All-cause mortality | 5.8 | Age, SBP, DBP, glucose, cholesterol, HDL-CH, BMI, education, procreation, smoking habit, alcohol use, ADLs, IADLs, depression and cognitive impairment |
| Stimpson et al, 2008 [38] | Mexico | Epidemiologic Studies of the Elderly, 1993–2000 (Hispanic EPESE) | 3,386 | 441 | 65 | Married | Widowed | All-cause mortality | 7 | Age, education, US nativity, financial strain, social support, health behaviors, medical conditions, disability, alcohol consumption, smoking, BMI, chronic conditions, lower body mobility, and depressive symptoms |
| Ikeda et al, 2007 [39] | Japan | Japan Collaborative Cohort Study | 94,062 | 8,365 | 56.8 | Married |
Never married Widowed Divorced/separated |
All-cause mortality Cancer mortality CVD mortality CHD mortality Stroke mortality |
9.9 | Age, BMI, smoking status, alcohol intake, education, minutes of walking, hours of doing sports, employment status, stress, having children, history of hypertension, and history of diabetes |
| Eaker et al, 2007 [20] | USA | The Framingham Offspring Study | 3,682 | NA | 48.5 | Married | Not married | All-cause mortality | 3 | Age, SBP, BMI, smoking, diabetes, total/high-density cholesterol |
| Jaffe et al, 2005 [41] | Israel | Israel Longitudinal Mortality Study | 131,156 | 2,7334 | 62.2 | Married | Not married | All-cause mortality | 9.5 | Age, Individual income, race, smoking, alcohol consumption, body mass index, and perceived health status |
| Nilsson et al, 2005 [42] | Sweden | The Malmo Preventive Project | 33,346 | 7,115 | 45.5 | Married/cohabiting |
Not married Widowed Divorced/separated |
All-cause mortality | 9.5 | Age and social class |
| Hurt et al, 2003 [43] | Bangladesh | Centre for Health and Population Research (ICDDR) | 29,606 | 1,233 | 46.5 | Married |
Widowed Divorced/separated |
All-cause mortality | 16 | Age, time, parity, own education, wife's education, religion, male occupation; area of residence, percentage of children surviving |
| Strand et al, 2004 [44] | Norway | NA | 44,684 | 6,506 | 42.1 | Married |
Not married Widowed Divorced/separated |
CHD mortality | 26 | Age, smoking, physical activity, BMI, diastolic blood pressure, systolic blood pressure, cholesterol |
| Malyutina et al, 2004 [45] | the Soviet Union | Novosibirsk MONICA Project | 11,404 | 1,602 | NA | Married |
Not married Never married Widowed Divorced/separated |
All-cause mortality CVD mortality CHD mortality Stroke mortality |
15.2 | Age, smoking, total cholesterol, systolic blood pressure, frequency of drinking, and BMI; total cholesterol, systolic blood pressure, frequency of drinking, BMI, education |
| Nagata et al, 2003 [46] | Japan | NA | 3,505 | 678 | 70.9 | Married |
Never married Widowed |
All-cause mortality | 7 | Age, number of children, years of education, smoking status, occupation (administrative/professional and the others), and alcohol intake |
| Johnson et al, 2000 [47] | USA | The National Longitudinal Mortality Study | 281,460 | 1,5364 | 58.3 | Married |
Never married Widowed Divorced/separated |
All-cause mortality | 11 | Age, Income, education, labor force status |
| Iwasaki et al, 2002 [48] | Japan | The Komo-Ise Study | 11,565 | 490 | NA | Married |
Never married Widowed Divorced/separated |
All-cause mortality Cancer mortality CHD mortality Stroke mortality |
7 | Age, area, occupation, educational background, smoking habit, alcohol consumption, BMI, chronic disease for men and these variables except for alcohol consumption for women |
| Breeze et al, 1999 [21] | UK | The Longitudinal Study | 93,931 | 63,405 | 63.7 | Married/cohabiting |
Never married Widowed Divorced/separated |
All-cause mortality | 10 | Age, social class, tenure and car availability |
| Fuhrer et al, 1999 [22] | France |
Personness Agées Quid (PAQUID) study |
3,777 | 849 | 73.2 | Married | Not married | All-cause mortality | 5 | Age, education, IADL, cognitive function, hospitalization in preceding year, smoking habits, alcohol consumption |
| Smith et al, 1997 [40] | USA | NA | 10,183 | 2,633 | 50.2 | Married | Not married |
All-cause mortality Cancer mortality CVD mortality |
14 | Age, race, alcohol consumption, serum cholesterol, hypertension status, BMI, baseline health, education, smoking status, physical exercise, household-level poverty |
| Nilsson et al, 1998 [34] | Sweden | The Swedish Annual Level-of-Living Survey (SALLS) | 39,055 | 4,897 | 48.1 | Married/cohabiting | Never married | All-cause mortality | 16 | Age, educational level, marital status, form of tenure, car ownership |
| NHIS, 2018 | USA | National Health Interview Survey | 339,113 | 62,245 | 45.3 | Married |
Never married Widowed Divorced/separated |
All-cause mortality Cancer mortality CVD mortality Stroke mortality |
8.4 | Age, sex, race, education, marital status, BMI, smoking, physical activity, drink, hypertension, diabetes, heart disease, stroke, cancer |
Abbreviations: BMI body mass index; CHD coronary heart disease; CVD cardiovascular disease; WHR waist hip rate; HRT hormone replacement therapy;ADL Activities of Daily Living; IADLs Instrumental Activities of Daily Living; SBP systolic blood pressure; DBP diastolic blood pressure; HDL-CH high density lipoprotein cholesterol; UK United Kingdom; USA United States of America; NA not available.