Table 1.
Descriptive statistics of included studies
| Study | Country | N | Age (years), mean (SD) unless otherwise stated | Women (%) | Follow-up (years) | HAQ – baseline, mean (SD) unless otherwise stated | HAQ – final follow-up, mean (SD) unless otherwise stated |
|---|---|---|---|---|---|---|---|
| Ahlmen [4] | SW | 549 | Women 54 (16) | 63 | 5 | Women 1.1 (0.6) | Women 0.7 (0.7) |
| Men 61 (13) | Men 0.8 (0.6) | Men 0.5 (0.6) | |||||
| Ajeganova [26] | SW | 1596 | 55.6 (14.6) | 68 | 15 | 1.0 (0.6) | 0.6 (0.6) |
| Andersson [43] | SW | 1430 | Immigrants (I) 55 (13) | I 76 | 15 | I 1.2 (0.7) | I 0.7 |
| Non-immigrants (non-I) 55 (14) | non-I 70 | Non-I 1.0 (0.6) | Non-I 0.6 (no SDs reported) | ||||
| Bansback [44] | UK | 985 | Median 55 | 66 | 5 | Median 1.0 | – |
| Benton [27] | NZ | 42 | Median (range) 48.5 (27–75) | 62 | 6 | Median (range) 0.6 (0–1.8) | Median (range) 0.3 (0–1.6) |
| Bjork [49] | SW | 189 | Women 53 (15) | 69 | 5 | Women 0.9 (0.6) | – |
| Men 58 (13) | Men 0.8 (0.5) | ||||||
| Burr [50] | UK | 463 | Median (IQR) 55.4 (45.8, 65.4) | 66 | 5 | Median (IQR) 0.9 (0.4, 1.5) | Median (IQR) 1.1 (0.4, 1.8) |
| Camacho [24] | UK | 3666 | <55 (%)/55–74 (%)/≥75 (%) | 66 | 15 | Median (IQR) | – |
| Women 53.6/37.6/8.8 | Women 0.9 (0.4, 1.6) | ||||||
| Men 41.3/46.0/12.7 | Men 0.6 (0.1, 1.3) | ||||||
| Camacho [29] | UK | 1872 | Median (IQR)Parous 54.3 (44.6, 65.2)Nulliparous 54.1 (36.4, 70.0) | 100 | 15 | Median (IQR) Parous 0.9 (0.4,1.6)Nulliparous 0.9 (0.4, 1.6) | – |
| Combe [34] | FR | 191 | 50.5 (14.7) | 73 | 5 | Median (range) 1.3 (0, 2.8) | Median (range) 0.6 (0, 3.0) |
| Combe [51] | FR | 813 | 48.1 (12.6) | 77 | 5 | 1.0 (0.7) | 0.5 (0.6) |
| Contreras-Yanez [25] | MX | 107 | 39.1 (13.3) | 89 | 5 | 1.5 (0.9, 2.1) | – |
| Eberhardt [28] | SW | 63 | 52.4 (13.7) | 62 | 5 | – | Women 0.9 (0.6) |
| Men 0.4 (0.4) | |||||||
| Eberhardt [52] | SW | 99 | 52.1 (12.8) | 67 | 5 | – | Medians ranged from 1.0 to 1.4 depending on immunogenetic group |
| Forslind [46] | SW | 92 | 53 (15) | 66 | 5 | Median (IQR) 1.0 (0.6, 1.4) | 0.4 (0.0, 1.1) |
| Genevay [23] | FR | 25 | 50.6 (15.5) | 72 | avg 8.5 | 0.8 (0.8) | – |
| Hallert [35] | SW | 251 | Women 55 (16) | 65 | 8 | Women 0.9 (0.6) | Women 0.9 (0.6) |
| Men 60 (14) | Men 0.8 (0.6) | Men 0.4 (0.4) | |||||
| Humphreys [40] | UK | 1995 | 55 (43, 66) | 66 | 20 | Median (IQR) 0.9 (0.4, 1.5) | – |
| Jäntti [33] | FIN | 121 | – | – | 20 | – | – |
| Kapetanovic [53] | SW | 183 | 52 (12) | 63 | 20 | 0.9 (0.6) | 1.1 (0.7) |
| Koevoets [39] | NL | 508 | 54 (13)–55 (14) | 86 | 5 | 1.4 (0.7) | 0.6 (0.6) |
| Kroot [38] | NL | 273 | ACPA+ 51.1 (15.1) | +ve 62 | 6 | ACPA+ 0.7 (0.4) | – |
| ACPA– 52.4 (14.8) | –ve 73 | ACPA– 0.7 (0.4) | |||||
| Kuiper [45] | NL | 332 | Postmenopausal women 66 (43–83) | 63 | 6 | – | – |
| Premenopausal women 36 (17–53) | |||||||
| Older men 63 (43–88) | |||||||
| Younger men 41 (23–53) | |||||||
| Kuuliala [48] | SW | 85 | 52.4 (range 18–78) | 64 | 5 | 0.8 (0.5, 1.2) | 0.9 (0.4, 1.3) |
| Lindqvist [54] | SW | 183 | 51.4 (12.4) | 63 | 10 | Median 0.8 (unreported IQR) | Median 1.1 (unreported IQR) |
| Ling [41] | UK | 2158 | Median 55 (43–67) | 65 | 5 | Median (IQR) 0.9 (0.3, 1.5) | Median (IQR) 0.9 (0.1, 1.6) |
| Malm [32] | SW | 1387 | 55 (14.1) | 70 | 15 | 1.0 (0.6) | – |
| Manivel [47] | SW | 773 | – | – | 5 | Median Anti-CII+ 1.0 | Median Anti-CII+ 0.5 |
| Anti-CII– 1.3 | Anti-CII– 0.6 | ||||||
| Nair [30] | NL | 1034 | 55 (14.5) | 66 | avg 6.5 | 1.2 (0.7) | – |
| Naseem [42] | UK | 843 | Median (IQR) 53 (40, 65) | 64 | 5 | Median (IQR) 0.8 (0.3, 1.4) | Median (IQR) 0.3 (0.3, 1.5) |
| Thyberg [55] | SW | 251 | 55 (14) | 68 | 8 | 0.9 (taken from figure) | 0.8 (taken from figure) |
| Verstappen [36] | NL | 112 | 49 (12.4) | 76 | avg 7 | 1.1 (0.7) | 0.7 (0.6) |
| Welsing [56] | NL | 378 | 54.8 (14.8) | 64 | 9 | Median (IQR) 0.5 (0.2,1.1) | 0.6 |
| Welsing [31] | NL | 185 | 55 | 64 | 9 | Median 0.5 | Median 0.6 |
| Wiles [37] | UK | 684 | Median (IQR) 55 (42, 68) | 67 | 5 | Median (IQR) 0.8 (0.3, 1.5) | Median (IQR) 0.9 (0.3, 1.6) |
| Wiles [57] | UK | 528 | 53 (41–66) | 67 | 5 | – | Median (IQR) 0.9 (0.3, 1.6) |
| Woolf [58] | UK | 88 | 45 | 72 | 5 | – | – |
ACPA = anti-citrullinated protein antibodies, Anti-CII = anticollagen type II antibodies, FIN = Finland, FR = France, HAQ = Health Assessment Questionnaire, IQR = Interquartile range, MX = Mexico, NL = The Netherlands, NZ = New Zealand, RA = rheumatoid arthritis, SD = standard deviation, SW = Sweden, UK = United Kingdom.