Clinical Characteristics and Patient-Reported Outcomes of Primary Care Physiotherapy in Patients with Whiplash-Associated Disorders: A Longitudinal Observational Study

BACKGROUND: Whiplash-associated disorders (WADs) constitute a state of health characterized by a wide diversity of symptoms as a result of impairments of functions, activity limitations, and participation restrictions. Patient-reported outcome measurements (PROMs) and patient-reported outcomes (PROs) seem appropriate when describing and evaluating the health status of patients with WAD. AIM: To measure the use of PROMs and PROs as quality indicators in clinical reasoning, and to analyze and evaluate pre- and post-treatment ‘pain intensity’ and ‘functioning’, and for ‘perceived improvement’ in patients with WAD in primary care physiotherapy practice by year of referral, with the phase after accident and prognostic health profile embedded in the clinical reasoning process. MATERIALS AND METHODS: Data were collected over a period of 10 years. Pain intensity, functioning, and perceived improvement were measured using the Visual Analogue Scale for Pain (VAS-P), the Neck Disability Index (NDI) and the Global Perceived Effect scale (GPE). Pre- and post-treatment mean differences were tested for statistical significance and compared to minimal clinically important differences (MCID). Effect sizes were expressed as Cohen’s d. Multivariable regression analysis was performed to explore independent associations of year of referral, phase after the accident, and the patient’s prognostic health profile with post-treatment pain intensity and functioning. RESULTS: A consecutive sample of 523 patients was included. Pre- and post-treatment mean differences on VAS-P and NDI were statistically significant (P<0.000) and clinically relevant, with ‘large’ effect sizes for pain intensity and functioning. MCIDs were achieved by 80% for VAS-P and for 60% for NDI. Year of referral and phase after the accident were independently associated with worse post-treatment functioning. About half of the patients (n=241 [46.1%]) perceived themselves as improved. CONCLUSION: The PROMs and PROs pain intensity, functioning and perceived improvement were integrated as quality indicators in the physiotherapy clinical reasoning process for patients with WAD. Significant differences in pain intensity and functioning were found but were unrelated to year of referral, phase after whiplash-related injury or prognostic health profile. The MCID VAS-P scores did not differ depending on experienced pain.