Rob AB Oostendorp,1– 4 JW Hans Elvers,5,6 Emiel van Trijffel,7,8 Geert M Rutten,9,10 Gwendolyne GM Scholten-Peeters,11 Marcel Heijmans,4 Erik Hendriks,12,13 Emilia Mikolajewska,14,15 Margot De Kooning,3,16 Marjan Laekeman,17,18 Jo Nijs,3,16,19 Nathalie Roussel,20 Han Samwel21 1Scientific Institute for Quality of Healthcare, Radboud University Nijmegen Medical Centre, Nijmegen, the Netherlands; 2Department of Manual Therapy, Faculty of Medicine and Pharmacy, Vrije Universiteit Brussel, Brussels, Belgium; 3Pain in Motion International Research Group, Department of Physiotherapy, Human Physiology and Anatomy, Faculty of Physical Education and Physiotherapy, Vrije Universiteit Brussel, Brussels, Belgium; 4Practice Physiotherapy and Manual Therapy, Heeswijk-Dinther, the Netherlands; 5Department of Public Health and Research, Radboud University Nijmegen Medical Centre, Nijmegen, the Netherlands; 6Department of Allied Health Care, Methodological Health-Skilled Institute, Beuningen, the Netherlands; 7Department of Master Education, SOMT University of Physiotherapy, Amersfoort, the Netherlands; 8Department of Physiotherapy, Human Physiology and Anatomy, Faculty of Physical Education and Physiotherapy, Vrije Universiteit Brussel, Brussels, Belgium; 9Institute of Health Studies, Faculty of Health and Social Studies, HAN University of Applied Science, Nijmegen, the Netherlands; 10Campus Venlo, Faculty of Science and Engineering, Maastricht University, Maastricht, the Netherlands; 11Department of Human Movement Sciences, Faculty of Behavioral and Movement Sciences, Vrije Universiteit Amsterdam, Amsterdam Movement Sciences, Amsterdam, the Netherlands; 12Department of Epidemiology, Center of Evidence Based Physiotherapy, Maastricht University, Maastricht, the Netherlands; 13Practice Physiotherapy ‘Maasstaete, Druten, the Netherlands; 14Department of Physiotherapy, Ludwik Rydygier Collegium Medicum in Bydgoszcz, Nicolaus Copernicus University, Toruń, Poland; 15Neurocognitive Laboratory, Centre for Modern Interdisciplinary Technologies, Nicolaus Copernicus University, Toruń, Poland; 16Department of Physical Medicine and Physiotherapy, University Hospital Brussels, Brussels, Belgium; 17Department of Nursing Sciences, Ph.D.-Kolleg, Faculty of Health, University Witten/Herdecke, Witten, Germany; 18Department of Physiological Psychology, University of Bamberg, Bamberg, Germany; 19Institute of Neuroscience and Physiology, University of Gothenburg, Gothenburg, Sweden; 20Department of Physiotherapy and Rehabilitation Sciences (MOVANT), Faculty of Medicine and Health Sciences, University of Antwerp, Antwerp, Belgium; 21Revalis Pain Rehabilitation Centre, S Hertogenbosch, the NetherlandsCorrespondence: Rob AB OostendorpScientific Institute for Quality of Healthcare, Radboud University Nijmegen Medical Centre, p/a Oude Kleefsebaan 325, AT Berg En Dal 6572, Nijmegen, the NetherlandsTel +31 246423419Email oostendorp.rob@gmail.comBackground: 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.Keywords: whiplash-Associated Disorders, neck pain, physiotherapy, patient-reported outcomes measures, routinely collected data