To evaluate the validity and reliability of the Dutch STarT MSK tool in patients with musculoskeletal
pain in primary care physiotherapy.
Physiotherapists included patients with musculoskeletal pain, aged 18 years or older.
Patients completed a questionnaire at baseline and follow-up at 5 days and 3 months,
respectively. Construct validity was assessed by comparing scores of STarT MSK items
with reference questionnaires. Pearson’s correlation coefficients were calculated to test predefined
hypotheses. Test-retest reliability was evaluated by calculating quadratic-weighted
kappa coefficients for overall STarT MSK tool scores (range 0–12) and prognostic subgroups
(low, medium and high risk). Predictive validity was assessed by calculating relative
risk ratios for moderate risk and high risk, both compared with low risk, in their ability to predict
persisting disability at 3 months.
In total, 142 patients were included in the analysis. At baseline, 74 patients (52.1%) were
categorised as low risk, 64 (45.1%) as medium risk and 4 (2.8%) as high risk. For construct
validity, nine of the eleven predefined hypotheses were confirmed. For test-retest reliability,
kappa coefficients for the overall tool scores and prognostic subgroups were 0.71 and 0.65,
respectively. For predictive validity, relative risk ratios for persisting disability were 2.19
(95% CI: 1.10–4.38) for the medium-risk group and 7.30 (95% CI: 4.11–12.98) for the highrisk
The Dutch STarT MSK tool showed a sufficient to good validity and reliability in patients with
musculoskeletal pain in primary care physiotherapy. The sample size for high-risk patients
was small (n = 4), which may limit the generalisability of findings for this group. An external
validation study with a larger sample of high-risk patients (�50) is recommended.