Table 1. Overview of the 148 studies included in the meta-analysis.
Source | Total Number of Participants | Average Age at Intake | Location of Study | Study Length | Cause of Mortality | Social Relationship Measure | Original Statistic Metric | lnOR | Standard Error |
Ahern et al., 1990 [29] | 353 | 50 | USA | 1 y | All-cause | Functional | M & SD | 0.27 | 0.36 |
Alter et al., 2006 [30] | 3,138 | 64 | Canada | 5 y 4 m | CVD | Combined | Chi | 0.06 | 0.15 |
Anstey et al., 2002 [31] | 2,065 | 78 | Australia | 9 y | All-cause | Structural | Freq | 0.44 | 0.09 |
Astrand et al., 1989 [32] | 391 | 50 | Sweden | 22 y | All-cause | Combined | OR | 0.00 | 0.18 |
Avlund et al., 1998 [33] | 727 | 70 | Denmark | 11 y | All-cause | Combined | OR | 0.40 | 0.16 |
Avlund et al., 2004 [34] | 565 | 75 | Denmark, Finland | 5 y | All-cause | Structural | OR | 0.54 | 0.22 |
Barefoot et al., 2005 [35] | 3,109 | 58 | Denmark | 7 y 2 m | All-cause | Structural | p | 0.15 | 0.12 |
Berkman and Syme, 1979 [36] | 4,765 | 47 | USA | 9 y | All-cause | Structural | Freq | 0.60 | 0.30 |
Berkman et al., 2004 [37] | 3,495 | 45 | France | 10 y | All-cause | Structural | RR | 1.61 | 0.14 |
Birket-Smith et al., 1989 [38] | 128 | 73 | Denmark | 1 y | All-cause | Structural | R | 0.37 | 0.33 |
Blazer, 1982 [39] | 331 | 72 | USA | 2 y 6 m | All-cause | Combined | RR | 1.05 | 0.30 |
Blazer et al., 2001 [40] | 3,664 | 73 | USA | 3 y | All-cause | Combined | OR | 0.15 | 0.10 |
Bowling, 1989 [41] | 503 | 73 | UK | 6 y | All-cause | Structural | Chi | 0.51 | 0.16 |
Brown et al., 2003 [42] | 846 | NR | USA | 5 y | All-cause | Combined | OR | 0.01 | 0.22 |
Brummet et al., 2005 [43] | 2,711 | 62 | USA | 11 y 1m | All-cause | Functional | p | 0.25 | 0.17 |
Burg et al., 2005 [44] | 1,899 | 75 | USA | 2 y 5 m | All-cause | Combined | Freq | 1.39 | 0.28 |
Burns et al., 2005 [45] | 147 | 63 | Australia | 7 y 4 m | Cancer | Combined | Combin | 0.45 | 0.31 |
Butow et al., 1999 [46] | 125 | 55 | Australia | 2 y | Cancer | Combined | p | 0.35 | 0.33 |
Bygren et al., 1996 [47] | 12,675 | 43 | Sweden | 9 y | All-cause | Structural | Freq | 0.41 | 0.07 |
Case et al., 1992 [48] | 1,195 | 59 | Canada, USA | 4 y 2 m | CVD | Structural | RR | 0.68 | 0.25 |
Cassileth et al., 1988 [49] | 203 | 60 | USA | 8 y | Cancer | Structural | Combin | −0.03 | 0.26 |
Ceria et al., 2001 [50] | 1,786 | 78 | USA | 6 y | All-cause | Structural | RR | 1.01 | 0.12 |
Chacko et al., 1996 [51] | 94 | 53 | USA | 4 y 8 m | CVD | Functional | Chi | 0.92 | 0.39 |
Christensen et al., 1999 [52] | 133 | 29 | USA | 58 y 2m | All-cause | Combined | Chi | 0.98 | 0.32 |
Christensen et al., 1994 [53] | 78 | 54 | USA | 5 y | All-cause | Functional | Chi | 0.98 | 0.44 |
Cohen et al., 1987 [54] | 155 | 73 | USA | 3 y | All-cause | Structural | T | 0.65 | 0.30 |
Colon et al., 1991 [55] | 100 | 30 | USA | 2 y | Cancer | Functional | Chi | 0.86 | 0.38 |
Cornman et al., 2003 [56] | 4,049 | NR | Taiwan | 3 y | All-cause | Structural | OR | 0.17 | 0.06 |
Coyne et al., 2001 [57] | 189 | 53 | USA | 4 y | CVD | Functional | RR | 0.99 | 0.26 |
Cree et al., 2000 [58] | 558 | 82 | Canada | 4 m | All-cause | Functional | OR | 0.30 | 0.34 |
Cuijpers, 2001 [59] | 424 | 85 | Netherlands | 1 y | All-cause | Functional | OR | −0.10 | 0.31 |
Dalgard & Haheim, 1998 [60] | 1,002 | 46 | Norway | 17 y | All-cause | Structural | p | 0.23 | 0.15 |
Devins et al., 1990 [61] | 97 | 40 | Canada | 4 y | Other | Structural | R | −0.025 | 0.38 |
Dickens et al., 2004 [62] | 556 | 60 | UK | 1 y | CVD | Functional | p | 0.65 | 0.45 |
Ell et al., 1992 [63] | 294 | 61 | USA | 6 y 11m | All-cause | Combined | p | −0.15 | 0.21 |
Eng et al., 2002 [64] | 16,242 | 55 | USA | 10 y | All-cause | Structural | RR | 0.42 | 0.06 |
Engedal,1996 [65] | 334 | 82 | Norway | 3 y | All-cause | Structural | M & SD | 0.62 | 0.20 |
Farmer et al., 1996 [66] | 320 | 60 | USA | 4 y 7m | All-cause | Combined | RR | 0.81 | 0.22 |
Forster & Stoller, 1992 [67] | 363 | 74 | USA | 7 y | All-cause | Combined | LnOR | −0.20 | 0.22 |
Frasure-Smith et al., 2000 [68] | 887 | 59 | Canada | 1 y | CVD | Functional | p | 0.09 | 0.12 |
Frick et al., 2005 [69] | 99 | 55 | Germany | 3 y 11m | Cancer | Combined | p | 0.23 | 0.35 |
Fry and Debats, 2006 [70] | 380 | 75 | Canada | 5 y 11m | All-cause | Combined | RR | 0.78 | 0.24 |
Fuhrer et al., 1999 [71] | 3,777 | 76 | France | 5 y | All-cause | Combined | RR | 0.38 | 0.13 |
Funch & Marshall, 1983 [72] | 208 | 51 | USA | 20 y | Cancer | Structural | Combin | 0.17 | 0.26 |
Ganzini et al., 1997 [73] | 100 | 73 | USA | 2 y 6m | All-cause | Combined | Combin | 0.15 | 0.25 |
Gellert et al., 1993 [74] | 136 | 47 | USA | 10 y | Cancer | Functional | RR | −0.24 | 0.40 |
Giles et al., 2005 [75] | 1,477 | 80 | Australia | 10 y | All-cause | Structural | p | 0.21 | 0.10 |
Giraldi et al., 1997 [76] | 74 | 51 | Italy | 6 y | Cancer | Functional | M & SD | 0.14 | 0.43 |
Glass et al., 1999 [77] | 1,380 | 72 | USA | 13 y | All-cause | Structural | RR | 0.42 | 0.20 |
Goldman et al., 1995 [78] | 7,478 | 77 | USA | 6 y | All-cause | Structural | OR | 0.30 | 0.06 |
Goodwin et al., 1996 [79] | 328 | 72 | USA | 10 y | All-cause | Structural | p | 0.62 | 0.20 |
Gorkin et al.,1993 [80] | 1,146 | 61 | USA | 10 m | All-cause | Functional | Freq | 0.23 | 0.28 |
Grand et al., 1990 [81] | 645 | 75 | France | 4 y | All-cause | Combined | OR | 0.40 | 0.22 |
Greenfield et al., 2002 [82] | 5,092 | NR | USA | 11 y | All-cause | Structural | RR | 0.38 | 0.14 |
Greenwood et al., 1995 [83] | 1,274 | 59 | UK | 4 y | All-cause | Structural | RR | 0.43 | 0.17 |
Grodner et al., 1996 [84] | 110 | 63 | USA | 6 y | All-cause | Combined | M & SD | 0.50 | 0.35 |
Gustafsson et al., 1998 [85] | 421 | 81 | Sweden | 6 y | All-cause | Structural | OR | 0.24 | 0.19 |
Hall et al., 1993 [86] | 5,921 | 60 | Sweden | 11 y | CVD | Structural | OR | 0.23 | 0.15 |
Helweg-Larsen, 2003 [87] | 6,617 | 44 | Denmark | 13 y | All-cause | Combined | RR | 0.74 | 0.05 |
Herndon et al., 1999 [88] | 206 | 61 | USA | 4 y 2 m | Cancer | Functional | p | 0.16 | 0.26 |
Hill et al., 2005 [89] | 3,050 | 78 | USA | 8 y | All-cause | Combined | p | 0.08 | 0.07 |
Hirdes & Forbes, 1992 [90] | 259 | 45 | Canada | 20 y | All-cause | Combined | RR | 0.55 | 0.29 |
Ho, 1991 [91] | 946 | 77 | China | 2 y | All-cause | Combined | RR | 0.55 | 0.24 |
House et al., 1982 [92] | 2,754 | 52 | USA | 12 y | All-cause | Structural | Combin | 0.27 | 0.17 |
Hummer et al., 1999 [93] | 21,204 | 43 | USA | 8 y | All-cause | Structural | Freq | 0.45 | 0.05 |
Iribarren et al., 2005 [94] | 5,108 | 25 | USA | 16 y | All-cause | Structural | Combin | 0.60 | 0.21 |
Irvine et al., 1999 [95] | 634 | 64 | Canada | 2 y | All-cause | Structural | RR | 0.01 | 0.32 |
Iwasaki et al., 2002 [96] | 11,560 | 55 | Japan | 7 y | All-cause | Combined | RR | 0.22 | 0.11 |
Johnson et al., 2005 [97] | 3,698 | 43 | USA | 5 y | All-cause | Combined | p | 0.18 | 0.10 |
Johnson et al., 1996 [98] | 1,257 | 64 | Sweden | 14 y | CVD | Functional | RR | 0.21 | 0.15 |
Jorm et al., 1991 [99] | 228 | 79 | Australia | 5 y | All-cause | Functional | M & SD | 0.24 | 0.24 |
Juon et al., 2003 [100] | 1,091 | 6 | USA | 28 y | All-cause | Structural | OR | 0.60 | 0.35 |
Jylhä and Aro, 1989 [101] | 936 | NR | Finland | 6 y 6 m | All-cause | Combined | p | 0.32 | 0.12 |
Kaplan et al., 1988 [102] | 5,320 | 49 | Finland | 5 y | All-cause | Structural | OR | 0.75 | 0.18 |
Kaplan et al., 1994 [103] | 2,501 | 53 | Finland | 5 y 11m | All-cause | Combined | RR | 0.27 | 0.19 |
Kawachi et al., 1996 [104] | 18,702 | 60 | USA | 4 y | All-cause | Structural | RR | 0.50 | 0.17 |
Keller et al., 2003 [105] | 654 | 78 | USA | 10 y | All-cause | Structural | p | 0.53 | 0.14 |
Kiely et al., 2000 [106] | 916 | 87 | USA | 4 y 6 m | All-cause | Structural | p | 0.23 | 0.12 |
Kimmel et al., 2000 [107] | 174 | 54 | USA | 5 y | All-cause | Functional | p | 0.73 | 0.17 |
Korten et al., 1999 [108] | 752 | 70 | Australia | 4 y | All-cause | Combined | Combin | 0.20 | 0.13 |
Krause, 1997 [109] | 2,209 | 68 | UK | 11 y | All-cause | Combined | OR | −0.03 | 0.10 |
Krause, 2006 [110] | 976 | 74 | USA | 3 y | All-cause | Combined | OR | 0 | 0.18 |
Kroenke et al., 2006 [111] | 2,835 | 59 | USA | 12 y | All-cause | Structural | RR | 0.45 | 0.22 |
La Cour et al., 2005 [112] | 734 | 70 | Denmark | 20 y | All-cause | Structural | p | 0.45 | 0.14 |
Lee & Rotheram-Borus, 2001 [113] | 307 | 38 | USA | 2 y 4 m | Other | Functional | p | 0.54 | 0.21 |
Lehto et al., 2006 [114] | 101 | 54 | Finland | 9 y | Cancer | Functional | p | 0.97 | 0.38 |
Lennartsson and Silverstein, 2001 [115] | 463 | 82 | Sweden | 4 y | All-cause | Structural | RR | 0.40 | 0.17 |
Ljungquist et al., 1995 [116] | 956 | 70 | Sweden | 10 y | All-cause | Combined | OR | 1.03 | 0.16 |
Lund et al., 2002 [117] | 1,265 | 60 | Denmark | 8 y | All-cause | Structural | p | 0.37 | 0.16 |
Lund et al., 2000 [118] | 894 | 79 | Denmark | 8 y | All-cause | Structural | OR | 0.30 | 0.21 |
Lyyra and Heikkinen, 2006 [119] | 206 | 80 | Finland | 10 y | All-cause | Combined | Combin | 0.25 | 0.30 |
Maier & Smith, 1999 [120] | 513 | 85 | Germany | 6 y | All-cause | Functional | Combin | 0.33 | 0.16 |
Malmstrom et al., 2001 [121] | 22,236 | 47 | Sweden | 8 y | All-cause | Structural | RR | 0.30 | 0.07 |
McClellan et al., 1993 [122] | 210 | 55 | USA | 1 y | All-cause | Functional | M & SD | 0.24 | 0.34 |
Merlo et al., 2000 [123] | 491 | 68 | Sweden | 10 y | All-cause | Combined | Freq | 0.63 | 0.19 |
Mertens et al., 1996 [124] | 1,869 | 62 | USA | 4 y | All-cause | Structural | M & SD | 0.56 | 0.08 |
Morris et al., 1993 [125] | 91 | 60 | USA | 10 y | All-cause | Structural | T | 0.81 | 0.40 |
Murata et al., 2005 [126] | 1,994 | 73 | Japan | 7 y 4 m | All-cause | Combined | p | 0.12 | 0.11 |
Murberg and Bru, 2001 [127] | 119 | 66 | Norway | 2 y | CVD | Combined | p | 0.27 | 0.34 |
Musick et al., 2004 [128] | 3,617 | 47 | USA | 7 y 6 m | All-cause | Combined | R | 0.17 | 0.06 |
Nakanishi and Tatara, 2000 [129] | 1,285 | 74 | Japan | 5 y 6 m | All-cause | Structural | p | 0.26 | 0.10 |
Nordentoft et al., 1993 [130] | 974 | 41 | Denmark | 10 y | All-cause | Structural | p | 0.42 | 0.12 |
Olsen et al., 1991 [131] | 1,637 | 79 | Denmark | 15 y 6m | All-cause | Combined | p | 0.14 | 0.11 |
Oman and Reed, 1998 [132] | 2,023 | 75 | USA | 5 y 7 m | All-cause | Structural | P | 0.20 | 0.11 |
Orrell et al., 2000 [133] | 60 | 80 | UK | 3 y | All-cause | Combined | p | 0.62 | 0.48 |
Orth-Gomer and Johnson, 1987 [134] | 17,433 | 49 | Sweden | 6 y | ? | Structural | RR | 1.31 | 0.07 |
Orth-Gomer and Unden, 1990 [135] | 147 | 57 | Sweden | 10 y | All-cause | Structural | T | 0.86 | 0.40 |
Ostbye et al., 2006 [136] | 4,012 | 77 | USA | 10 y | All-cause | Combined | OR | 0.54 | 0.09 |
Oxman et al., 1995 [137] | 232 | 76 | USA | 6 m | CVD | Combined | Combin | 0.33 | 0.46 |
Parkerson and Gutman, 2000 [138] | 103 | 63 | USA | 1 y | All-cause | Structural | OR | 1.65 | 0.58 |
Pennix et al., 1997 [139] | 2,829 | 70 | Netherlands | 3 y | All-cause | Combined | Freq | 0.30 | 0.15 |
Rasulo et al., 2005 [140] | 1,734 | 81 | Denmark | 6 y | All-cause | Structural | p | 0.11 | 0.09 |
Reuben et al., 1992 [141] | 259 | 73 | USA | 4 y 3 m | All-cause | Combined | R | 0.52 | 0.22 |
Reynolds et al., 1994 [142] | 1,011 | 53 | USA | 5 y | Cancer | Combined | p | 0.19 | 0.17 |
Rodriguez-Artalejo et al., 2006 [143] | 251 | 77 | Spain | 7 m | CVD | Structural | p | 0.17 | 0.33 |
Rosengren et al., 1998 [144] | 717 | 50 | Sweden | 12 y | All-cause | Combined | Freq | 0.64 | 0.28 |
Roy et al., 1996 [145] | 547 | 80 | USA | 4 y | All-cause | Structural | RR | 0.76 | 0.15 |
Rozzini et al., 1991 [146] | 1,201 | 73 | Italy | 3 y | All-cause | Structural | Freq | 0.94 | 0.20 |
Ruberman et al., 1984 [147] | 2,320 | 50 | USA | 3 y | All-cause | Structural | Chi | 0.39 | 0.08 |
Rutledge et al., 2003 [148] | 7,524 | 71 | USA | 6 y | All-cause | Combined | RR | 0.53 | 0.05 |
Rutledge et al., 2004 [149] | 503 | 59 | USA | 2 y 4 m | All-cause | Combined | M & SD | 0.99 | 0.37 |
Saito-Nakaya et al., 2006 [150] | 238 | 62 | Japan | 7 y 6 m | All-cause | Combined | Freq | −0.07 | 0.35 |
Schoenbach et al., 1986 [151] | 791 | 55 | USA | 2 y | All-cause | Structural | Freq | 0.80 | 0.19 |
Seeman et al., 1993 [152] | 1,420 | 74 | USA | 5 y | All-cause | Combined | p | 1.83 | 0.17 |
Shahatahmasebi et al., 1992 [153] | 534 | 72 | UK | 8 y | All-cause | Combined | Chi | 0.40 | 0.16 |
Shmotkin et al., 2003 [154] | 1,174 | 84 | Israel | 8 y | All-cause | Structural | p | −0.09 | 0.12 |
Shye et al., 1995 [155] | 455 | 72 | USA | 15 y | All-cause | Structural | Freq | 0.80 | 0.21 |
Silverstein and Bengston, 1991 [156] | 435 | 67 | USA | 14 y | All-cause | Combined | OR | 0.03 | 0.16 |
Soler-Vila et al., 2003 [157] | 322 | 54 | USA | 10 y | All-cause | Combined | M & SD | 0.29 | 0.20 |
Stavraky et al., 1988 [158] | 224 | 59 | Canada | 1 y | Cancer | Combined | Freq | 0.55 | 0.35 |
Stek et al., 2005 [159] | 476 | 85 | Netherlands | 5 y | All-cause | Functional | p | 0.35 | 0.21 |
Sturdy et al., 2002 [160] | 1,066 | 53 | UK | 5 y | All-cause | Structural | OR | 0.17 | 0.35 |
Sugisawa et al., 1994 [161] | 1,943 | 69 | Japan | 3 y | All-cause | Combined | p | 0.03 | 0.19 |
Sun and Lui, 2006 [162] | 7,938 | 92 | China | 2 y | All-cause | Structural | R | 0.67 | 0.04 |
Temkin-Greener et al., 2004 [163] | 3,138 | 79 | USA | 2 y | All-cause | Combined | p | 0.21 | 0.10 |
Thomas et al., 1997 [164] | 424 | 63 | Canada, USA | 3 y 11m | CVD | Functional | M & SD | 0.10 | 0.18 |
Tucker et al., 1996 [165] | 1,077 | 12 | USA | 41 y | All-cause | Structural | p | 0.27 | 0.12 |
Vaillant et al., 1998 [166] | 223 | 20 | USA | 25 y | All-cause | Combined | OR | 1.15 | 0.37 |
Vogt et al., 1992 [167] | 2,396 | 47 | USA | 15 y | All-cause | Structural | p | 0.20 | 0.08 |
Walter-Ginzburg et al., 2002 [168] | 1,340 | 83 | Israel | 8 y | All-cause | Combined | Freq | 0.23 | 0.11 |
Waxler-Morrison et al., 1991 [169] | 118 | 45 | Canada | 4 y | Cancer | Structural | p | 0.27 | 0.36 |
Weihs et al., 2005 [170] | 90 | 52 | USA | 9 y | Cancer | Structural | Combin | 0.61 | 0.40 |
Welin et al., 2000 [171] | 275 | 55 | Sweden | 10 y | All-cause | Combined | p | 0.44 | 0.22 |
Welin et al., 1992 [172] | 959 | 60 | Sweden | 12 y | All-cause | Combined | Combin | 0.52 | 0.17 |
Wilkins, 2003 [173] | 2,107 | 75 | Canada | 6 y | All-cause | Combined | RR | 0.05 | 0.12 |
Woloshin et al., 1997 [174] | 37 | 67 | Canada | 1 y | All-cause | Functional | OR | 1.87 | 0.61 |
Yasuda et al., 1997 [175] | 806 | 74 | USA | 5 y | All-cause | Combined | Freq | 0.27 | 0.19 |
Zuckerman et al., 1984 [176] | 398 | 72 | USA | 2 y | All-cause | Combined | Combin | 0.09 | 0.18 |
Chi, chi-square; Combin, combined statistics; Freq, frequency counts; m, months; M & SD, means and standard deviations; NR, not reported; OR, odds ratio; RR, risk ratio; p, level of statistical significance; t, t-scores; y, years.