Objective
To develop and internally validate a prognostic
model to predict chronic pain after a new episode of acute
or subacute non-specific
idiopathic, non-traumatic
neck
pain in patients presenting to physiotherapy primary care,
emphasising modifiable biomedical, psychological and
social factors.

Design
A prospective cohort study with a 6-month
follow-up
between January 2020 and March 2023.
Setting 30 physiotherapy primary care practices.
Participants Patients with a new presentation of non-specific
idiopathic, non-traumatic
neck pain, with a
duration lasting no longer than 12 weeks from onset.
Baseline measures Candidate prognostic variables
collected from participants included age and sex, neck
pain symptoms, work-related
factors, general factors,
psychological and behavioural factors and the remaining
factors: therapeutic relation and healthcare provider
attitude.

Outcome
measures Pain intensity at 6 weeks, 3 months
and 6 months on a Numeric Pain Rating Scale (NPRS) after
inclusion. An NPRS score of ≥3 at each time point was
used to define chronic neck pain.

Results
62 (10%) of the 603 participants developed
chronic neck pain. The prognostic factors in the final
model were sex, pain intensity, reported pain in different
body regions, headache since and before the neck pain,
posture during work, employment status, illness beliefs
about pain identity and recovery, treatment beliefs,
distress and self-efficacy.
The model demonstrated an
optimism-corrected
area under the curve of 0.83 and a
corrected R2 of 0.24. Calibration was deemed acceptable
to good, as indicated by the calibration curve. The
Hosmer–Lemeshow test yielded a p-value
of 0.7167,
indicating a good model fit.

Conclusion
This model has the potential to obtain a
valid prognosis for developing chronic pain after a new
episode of acute and subacute non-specific
idiopathic,
non-traumatic
neck pain. It includes mostly potentially
modifiable factors for physiotherapy practice. External
validation of this model is recommended.