Outcomes

The primary outcome measures were: neck disability (Neck Disability Index, NDI% [23]), and average pain intensity last week (0–10 Numeric Rating Scale, NRS [50]). The secondary outcomes included: (i) General improvement, measured with the Patient Global Impression of Change scale (PGICS) [50] which is a single question asking the participants for an estimation of change compared to before the intervention with a 7-point response Likert scale from 1. “very much improved” to 7. “very much worse” (ii) Intensity and frequency of symptoms, measured with the symptom scale, intensity and frequency indices, of the neck specific Profile Fitness Mapping neck questionnaire (ProFitMap-neck) [51]. The index scores are normalized 0-100 with higher scores reflecting less symptoms/better health. (iii) Self-reported work productivity loss, measured with questions of the impact of neck symptoms on the quality and quantity of performed work the latest six weeks [24] (response scale 0-10, 10 equals working as usual) and finally (iv) Pressure pain threshold (PPT) of m. trapezius, assessed with pressure algometer (unit, kPa). Any adverse events were recorded by the intervention leaders and reported to the project leader (MB) for documentation. If a participant in either the TT- or NTT- group experienced an acute pain episode during the intervention that did not settle within a week, the physiotherapist was permitted to assess and treat the problem with manual therapy, for a maximum of three sessions, to reduce the pain. It was considered unethical to withhold a treatment with proven effectiveness for neck pain [14]. This occurred only once during the intervention. The participant in question received three sessions of manual therapy and subsequently, the prescribed intervention could be carried through.