Table 1

Baseline characteristics of the STAP-study participants (n=185)

Total population
N=185
Custom-made insole
group
n=70
Sham insole
group
n=69
Usual care
group
n=46
Mean (SD) unless otherwise indicatedMean (SD) unless otherwise indicatedMean (SD) unless otherwise indicatedMean (SD) unless otherwise indicated
Age, y47.6 (10.6)48.0 (11.3)48.2 (9.4)46.1 (11.4)
Sex, female, No (%)128 (69.2)48 (68.6)48 (69.6)32 (69.6)
Educational level, No (%)
Low59 (31.9)23 (32.9)20 (29.0)16 (34.8)
Middle86 (46.5)29 (41.4)33 (47.8)24 (52.2)
High40 (21.6)18 (25.7)16 (23.2)6 (13.0)
BMI29.7 (5.3)29.2 (5.8)29.5 (4.8)30.9 (5.0)
Pain history
 Localization of complaints, bilateral, No (%)45 (24.3)16 (22.9)16 (23.2)13 (28.3)
 Duration of pain, mo6.2 (10.4)7.7 (15.5)5.1 (5.2)5.4 (5.6)
 VAS during rest (0–10)4.1 (2.6)3.8 (2.5)4.0 (2.7)4.9 (2.4)
 VAS during activity (0–10)6.8 (2.0)6.8 (2.0)6.7 (2.1)7.0 (1.8)
 VAS first step pain (0–10)7.2 (2.3)7.2 (2.4)7.3 (2.1)7.2 (2.5)
 DN4 (0–10>4indicates neuropathic pain)3.7 (2.1)3.9 (2.1)3.6 (1.8)3.7 (2.3)
 FFI total (0–100)48.7 (18.0)50.2 (18.8)46.1 (17.2)50.3 (18.0)
 FFI disability (0–100)39.6 (20.9)41.6 (23.1)37.3 (19.7)40.1 (19.3)
 FFI pain (0–100)58.7 (17.7)60.0 (16.7)55.6 (17.2)61.2 (19.6)
 FPDI function (9-27)17.5 (4.4)17.2 (4.2)17.6 (4.9)17.9 (4.2)
 Self-reported illness in the past 12 months, No (%)116 (62.7)45 (64.3)45 (65.2)26 (56.5)
 Other musculoskeletal pain at baseline, No (%)78 (42.2)29 (41.4)32 (46.4)17 (37.0)
Quality of life
 SF12 Physical health (0–100)38.2 (8.4)39.0 (8.4)37.9 (8.7)37.4 (7.8)
 SF12 Mental health (0–100)* 49.2 (10.1)46.9 (11.1)*51.2 (8.9)*49.5 (9.9)
 EQ-5D Utility score (0–1)0.7 (0.2)0.7 (0.3)0.7 (0.2)0.7 (0.2)
Activity level
 SQUASH7716.7 (5270.0)6761.3 (4525.5)8755.3 (5747.8)7612.6 (5398.8)
Self-reported interventions for PHP in the 3 months prior to inclusion
 Visit to GP, No (%)165 (89.2)60 (85.7)62 (89.9)43 (93.5)
 Visit to physiotherapist, No (%)15 (8.1)6 (8.6)5 (7.2)4 (8.7)
 Use of pain medication, No (%)73 (39.5)30 (42.9)25 (36.2)18 (39.1)
 Exercises, No (%)73 (39.5)26 (37.1)29 (42.0)18 (39.1)
 Shockwave, No (%)2 (1.1)2 (2.9)
 Dry Needling, No (%)1 (0.5)1 (1.4)
 Massage/ manipulation, No (%)4 (2.2)1 (1.4)3 (4.3)
 Custom insoles, No (%)1 (0.5)1 (1.4)
 Prefabricated orthotic, No (%)67 (36.2)29 (41.4)25 (36.2)13 (28.3)
 Shoe advice, No (%)14 (7.6)4 (5.7)8 (11.6)2 (4.3)
 Corticosteroid injection, No (%)3 (1.6)2 (2.9)1 (2.2)
  • *There was a mean difference of 4.28 (95% CI 0.18 to 8.38) on the mental health component of the SF12 between the sham insole group and the custom-made insole group, in favour of sham insole.

  • BMI, body mass index; DN4, Douleur Neuropathique 4; EQ-5D, EuroQol five dimension scale; FFI, Foot Function Index (total score and pain and disability subscales); FPDI, (Manchester) Foot Pain and Disability Index (function subscale); mo, months; No, number of participants; SF12, The 12-Item Short Form Health Survey; SQUASH, Short Questionnaire to Assess Health-enhancing Physical Activity; VAS, Visual Analogue Scale; y, years.