Stefan Elbers

39 Evaluating IMPT programmes over time Table 1. Continued. Author (year) cohort N Dropout (%) Lost to follow- up (%) Nationality % Females Mean age ( SD ) Patient group Mean pain duration (months) Gerdle (2016) 464 NA NA Sweden 81.6 38.1 (10.1) chronic pain 83.8 Grahn (2000) 236 NA NA Sweden 82 44.3 (9.1) prolonged musculoskeletal disease as main diagnosis 68.4 Gustafsson (2002) 23 4.35 22.73 Sweden 100 43.8 (10.7) fibromyalgia or widespread chronic pain 158.4 Hafenbrack (2013): a 681 2.86 55.51 Germany 49.2 45.81 (9.22) back pain NA Hafenbrack (2013): b 681 3.18 55.26 Germany 55.3 44.95 (9.84) back Pain NA Haiduk (2017) 115 NA NA Switzerland 83.1 40.3 (12.3) chronic neck pain 17.2 Hållstam (2016) 42 NA NA Sweden 90.5 43.6 (15.7) complex pain problems NA Hazard (1989) 64 1.69 31.03 USA 36 37 (4.3) low back pain NA Hildebrandt (1996) 98 1.1 6.67 Germany 48.9 41.7 (8.7) lumbal and unspecific back pain NA Huffman (2019) 2089 19.53 62.17 USA 65.3 46.6 (13.6) chronic non cancer pain NA Ibrahim (2019) 201 20.4 33.12 Switzerland 40.8 39.98 (10.06) non-specific LBP NA Jensen (1997): a 63 6.67 10.71 Sweden 100 43 (9) nonspecific spinal pain 51 Jensen (1997): b 63 6.06 6.45 Sweden 100 45 (8) nonspecific spinal pain 44 Kääpä (2006) 64 7.81 16.95 Finland 100 46 (7.9) low back pain 16 Koopman (2004) 68 5.88 20.31 Netherlands 47.1 41.3 (8.91) low back pain 72 Lemstra (2005) 43 16.28 2.78 Canada 86 49.7 (9.57) chronic widespread pain 121.7 Letzel (2019) 113 28.32 20.99 Germany 67.9 59.7 (10.7) chronic neck pain NA