Stefan Elbers

41 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) Richardson (1994) 109 9.17 -10.1 United Kingdom 68 45 (10) chronic pain 128 Roche- Leboucher (2011) 132 NA NA France 32.4 40.8 (7.4) non-specific low back pain NA Semrau (2015) 554 5 27.44 Germany 54.1 48.9 (8) low back pain NA Silvemark (2014) 164 13.64 48.87 Sweden 69.5 37.4 (9.07) long-term non- malignant pain 68.4 Smeets (2008): a 223 5.17 5.45 Netherlands 58.6 42.52 (9.67) non-specific low-back pain 68.33 Smeets (2008): b 223 9.84 3.64 Netherlands 37.7 40.67 (10.14) non-specific low-back pain 56.13 Spinhoven (2004) 148 11.97 12.62 Netherlands 63.5 39.8 (9.1) low back pain 117.6 Stein (2013) 59 0 13.56 Sweden 86 48 (7.8) chronic non- cancer pain NA Steinmetz (2019) 276 9.78 56.22 Germany 57.4 53.4 (10.6) chronic spinal pain Strobel (1998) 32 NA NA Germany 87.5 49 (7.5) fibromyalgia (ACR criteria) 92.4 Tavafian (2011) 197 4.12 25.81 Iran 73.2 44.6 (10.2) chronic low back pain 75.9 Thieme (2003) 61 4.76 0 Germany 100 46.61 (8.67) fibromyalgia 204.6 Van der Maas (2015): a 114 42.11 21.21 Netherlands 71.1 45.4 (11.1) chronic musculoskeletal pain NA Van der Maas (2015): b 114 8.16 48.89 Netherlands 91.8 38.6 (11.1) chronic musculoskeletal pain NA van Hooff (2010) 107 23.36 0 Netherlands 57 44.1 (8.4) low back pain 147.6 van Wilgen (2009) 32 18.75 0 Netherlands 73 42 (11) chronic pain 96 Vendrig (2000) 147 NA NA Netherlands 31 41.6 (8.5) chronic low back pain 46.3