Background Back pain is among the most frequent reasons for care seeking globally. Observational clinical cohorts are useful for understanding why people seek care, the content of that care, and factors related to prognosis. This paper describes the Danish Chiropractic low back pain Cohort (ChiCo) and summarizes the primary characteristics of the population to inform the scientific community of the availability of these data as a resource for collaborative research projects. Methods Adults seeking chiropractic care for a new episode of non-specific back pain were enrolled at the initial visit and followed up after 2, 13, and 52 weeks, with a subpopulation having weekly follow-ups for 1 year. Patient-reported and clinical-reported data were collected in an electronic database using the REDCap software (REDCap Consortium, projectredcap.org). Variables were chosen to measure pre-defined research domains and questions and to capture information across health constructs deemed relevant for additional research. Non-responders at 13 and 52 weeks were contacted by phone to maximize follow-up data and explore differences on core outcomes between responders and non-responders. Results A total of 2848 patients (mean age 45 years, 59% men) were included from 10 clinics with 71%, 68% and 64% responding to follow-ups at 2, 13 and 52 weeks, respectively. Most participants (82%) were employed, nearly half reported current LBP for 1–7 days, and 83% had experienced LBP episodes previously. We did not identify indications of serious attrition bias. Conclusion We have described the aims and procedures for establishing the ChiCo cohort, characteristics of the cohort, and available information about attrition bias. These data have the potential to be linked, at an individual participant level, to the extensive Danish population-based registries that measure diverse health and social characteristics.

BackgroundThe chiropractic profession has been well established in Denmark for several decades with state authorization, partial reimbursement by the state and a formal academic education. Biennial systematic data collections among all chiropractors and clinics have been performed since 2010 in order to provide exact information on the profession to The Danish Chiropractic Association (DCA). It is the aim of this study to outline the major characteristics and developments of the chiropractic profession in Denmark to make this information accessible to other stakeholders, domestic as well as foreign.MethodsUsing contact information from the DCA, two questionnaires were distributed electronically to all individual members of the association actively working as chiropractors and all clinics respectively in 2010, 2012 and 2014. The questions asked were developed for this specific survey.ResultsResponse rates varied between 59 and 78 % for the clinic questionnaires and 75 to 86 % for the individual questionnaires. Almost half the Danish chiropractors were educated in Denmark and a small majority was female. The average Danish chiropractor of 2014 was 44 years old, graduated 17 years earlier, and worked full time in a primary care clinic with at least one colleague. Half the chiropractors spent more than 20 h a year on continued professional development. Danish chiropractic clinics had a median of 3 treatment rooms, most had digital X-ray equipment, around 6 out of 10 had exercise facilities, and 1 out of 4 employed a physiotherapist. Three out of 4 clinics employed a secretary, too. The average duration of a consultation was 40 min for a new patient and 13 min for a follow-up consultation. Virtually all Danish chiropractors working in the primary sector made use of manipulation as one of their treatment modalities.ConclusionThis is the first study to describe the state and latest development of the chiropractic profession in Denmark using repeated surveys. Displaying various characteristics of both clinics and individual chiropractors, the image emerging is one of a stable profession where rapid or drastic changes are not taking place over short intervals of time.