Our investigation revealed clear themes confirming previous results from quantitative studies [1, 2, 6–8, 12, 13]. In particular, as seen in other contexts, Danish chiropractors regard MC primarily as a means of providing secondary or tertiary care, it is recommended to patients with a history of recurrence, the initiation of MC is often a shared decision between chiropractor and patient, the use of MC relates to the chiropractor’s education and clinical experience, the core element of MC is examination and manipulation, but also commonly includes exercise and general lifestyle advice and finally the typical interval between consultations is 2–4 months.
In addition to these confirmatory observations our investigation also revealed that in the local context chiropractors were more likely to offer MC to patients whose complaints included a significant muscular component, that a successful transition to MC appears dependent on a correct matching of complaint and management, that a positive relationship between chiropractor and patient facilitates the initiation of MC, and finally that MC rests in the tenet patient-oriented care rather than market-oriented. Previous studies have indicated that the patient needs to respond positively to chiropractic care before MC is offered, but this issue did not emerge in the present study. Whether this is because the interviewed chiropractors did not find it important, or whether they considered it obvious and therefore didn’t mention it, is unknown.
We selected as broad a range of Danish chiropractors and conducted enough interviews to reach the point of saturation. We also believe our data to be trustworthy due to the nature of the interviews and the apparent trust between the interviewees and the research team. However, the nature of this type of investigation precludes us from inferring a generalizable truth about MC in Denmark. Nevertheless, these results are synergistic to other investigations on this topic and as such it seems fair to consider results from the present study as relevant indicators for the Danish chiropractors’ view on MC.
The concept of MC as secondary or tertiary prophylaxis varies somewhat from the most common perception of prophylaxis, which focuses on primary prevention, i.e. to prevent disease from occurring. Typical examples of the latter include vaccines for communicable diseases or condoms to avoid sexually transmitted diseases (STDs), where the purpose is primary prevention. However, in public health, many initiatives aimed at primary prophylaxis also function as secondary or tertiary prophylactics. For example physical exercise may prevent cardiovascular disease; however, it also serves to regulate blood pressure after the onset of the disease.
MC practices are not unique to the chiropractic profession. In dentistry, MC is intended to avoid caries and periodontal disease through fluoride therapy and improved dental hygiene. However, if such disease occurs despite the primary prevention strategy, secondary preventative treatment takes effect to avoid exacerbation. Thus, the concept is generally recognized in society in other health domains and the implicit overall aim is to decrease the burden of disease and thereby also reduce the cost of health care.
Low back pain is now the leading cause of disability globally measured in years lived with disability (YLD) with 1206 YLD per 100,000 in 2010 and neck pain is number four with 488 YLD per 100.000 (GBD 2013). This represents an increase of 33.3% since 1990, largely driven by population growth and ageing . Thus, these figures are likely to continue to increase. Parallel to this, there has been a significant increase in the consumption of painkillers, i.e. the sale of opioid analgesics has quadrupled between 1999 and 2010 . Considering that more than 100.000 deaths per year can be attributed to adverse effects of medication in the US alone  as well as non-quantifiable morbidity, non-pharmaceutical prophylactic strategies deserve attention and for the musculoskeletal system chiropractic care might be an option. Limited evidence is currently available with respect to the effectiveness of MC strategies initiated by chiropractors. As stated previously, the RCTs available have included consecutive patients without consideration of either factors qualifying patients for MC in practice or individual care requirements. Therefore, these RCTs are unlikely to reflect clinical reality, and we suggest that investigators consider such factors and requirements in future studies, especially when planning RCTs.