J Manipulative Physiol Ther 2007 (Mar); 30 (3): 165–170 ~ FULL TEXT
Michael J. Garner, Peter Aker, MSc, DC, Jeff Balon, DC, MD, Michael Birmingham, PhD,
David Moher, PhD, Dirk Keenan, DC, Pran Manga, PhD
Carlington Community and Health Services,
Ottawa, Ontario, Canada.
OBJECTIVE: This study was part of a larger demonstration project integrating chiropractic care into publicly funded Canadian community health centers. This pre/post study investigated the effectiveness of chiropractic care in reducing pain and disability as well as improving general health status in a unique population of urban, low-income, and multiethnic patients with musculoskeletal (MSK) complaints.
METHODS: All patients who presented to one of two community health center-based chiropractic clinics with MSK complaints between August 2004 and December 2005 were recruited to participate in this study. Outcomes were assessed by a general health measure (Short Form-12), a pain scale (VAS), and site-specific disability indexes (Roland-Morris Questionnaire and Neck Disability Index), which were administered before and after a 12-week treatment period.
RESULTS: Three hundred twenty-four patients with MSK conditions were recruited into the study, and 259 (80.0%) of them were followed to the study's conclusion. Clinically important and statistically significant positive changes were observed for all outcomes (Short Form-12: physical composite score mean change = 4.9, 95% confidence interval [CI] = 3.8-6.0; VAS: current pain mean change = 2.3, 95% CI = 1.9-2.6; Neck Disability Index: mean change = 6.8, 95% CI = 5.4-8.1; Roland-Morris Questionnaire: mean change = 4.3, 95% CI = 3.6-5.1). No adverse events were reported.
CONCLUSIONS: Patients of low socioeconomic status face barriers to accessing chiropractic services.
This study suggests that chiropractic care reduces pain and disability as well as improves general health status in patients with MSK conditions. Further studies using a more robust methodology are needed to investigate the efficacy and cost-effectiveness of introducing chiropractic care into publicly funded health care facilities.
From the Full-Text Article:
Description of the Study Sample and Follow-Up
Three hundred sixty-six individuals presented to the chiropractic clinics over the 17 months of study. Three hundred twenty-four met our eligibility criteria, and all consented to be enrolled in this study and receive treatment. Two hundred fifty-nine (80.0%) were followed to discharge and completed all appropriate questionnaires. Sixty-five (20.0%) participants were lost to follow-up: 48 (74%) for failing to attend the clinic, 5 (8%) for mental and physical health issues, 4 (6%) for family and legal issues, 5 (8%) because they were referred out of the clinic to more appropriate providers, and 3 (4%) because of multiple issues.
The baseline characteristics of the sample are described in Table 1. Of the participants, 73% were female, 34% were married, and 62.2% had a household income (in Canadian dollars) lower than $20,000 per year, with an average household size of 2.8 persons (the poverty line in 2004 for 1 person was $20,33716). Almost 60% of the participants were referred to the chiropractor by one of the health care practitioners at the CHC, and the rest presented themselves for care. Most of them reported neither smoking (78.8%) nor drinking (65.3%). Eighty-three percent of the participants presented to the chiropractor with a chronic complaint (>3 months' duration).
On average, the patients received 7.6 treatments (SD = 4.3) during the 12-week treatment period. The number of treatments did not vary by clinic site, sex, or age but was slightly different by condition type (acute = 6.0, chronic = 7.9). No adverse events were reported or observed.
Visual Analog Scale for Pain
We observed clinically important and statistically significant changes in reported current (mean score = 2.3, 95% confidence interval [CI] = 1.9-2.6) and typical (mean score = 2.0, 95% CI = 1.7-2.3) pain in all patients (Table 2). Post hoc analyses showed that change remained positive when we stratified by acute and chronic conditions, high and low BMI, and sex.
The total change score for those patients with LBP (RMQ) was a point reduction of 4.3 in disability (95% CI = 3.6-5.1). This change is clinically important and statistically significant (Table 3). For those patients with neck pain, there was a clinically important and statistically significant reduction in neck-related disability (6.8, 95% CI = 5.4-8.1). The results for the NDI did not change when using the two methods for imputing missing data. In the post hoc analyses, when we stratified by chronicity, sex, or BMI, the changes remained positive for the RMQ and NDI.
General Health Outcomes (SF-12v2)
Positive and clinically important changes were observed for the PCS (total change = 4.9, 95% CI = 3.8-6.0) and MCS (total change = 3.2, 95% CI = 2.0-4.3) (Table 4). Post hoc analyses revealed little change in outcome when we stratified by acute and chronic conditions, sex, or BMI. However, the participants with a household income lower than $20,000 per year reported lower PCSs before and after treatment as compared with those who had an income higher than $20,000 per year.
Patients indicated satisfaction with the care provided by the chiropractor, with 78.8% of them being “very satisfied” and 18.9% being “satisfied.”
Withdrawals, Dropouts, and Missing Data
In comparing patients with complete data with those who were lost to follow-up, the participants were found to be the same on all demographic variables except sex; male participants accounted for 40% of the lost sample and 27% of the analyzed sample. For participants who withdrew or dropped out but for whom we had initial questionnaire data (VAS, RMQ, NDI, and SF-12v2), we imputed a value of no change and reran the statistical analysis. No meaningful change in effect was observed.
Most of the participants in our study sample were below the poverty line (<$20,000 per year) and had minimal education (lower than grade 12). They were also of mixed ethnicity and from an urban environment, and most had chronic rather than acute conditions. This sample is uniquely different from the usual population (ie, largely of middle to upper class, white, and presenting with acute MSK conditions) cared for by chiropractors.  Descriptions of chiropractic treatment in populations of low socioeconomic status are rare.
Populations in lower socioeconomic strata have higher incidence and prevalence rates of LBP and MSK conditions in general (in addition to other health problems), yet they have the least access to chiropractic care.  In addition to barriers in accessing adequate and appropriate traditional medical services, nontraditional or complementary and alternative health care services such as chiropractic are also inaccessible for most CHC clients because of the costs associated with treatment outside of Canada's publicly funded health care system. Adding chiropractic to the multidisciplinary health care teams in CHCs improved access to appropriate health services for the CHC clients' clinical problems and, as we report in this article, improved their outcomes of care. We observed good interprofessional rapport and teamwork between the medical doctors and the chiropractors at both sites. The limited access to alternatives to standard medical care results in most MSK disorders in CHCs being treated with anti-inflammatory medication, which has significant associated risks. [18, 19] Chiropractic care offers a viable alternative to medication, with potentially less risk.  No adverse event was observed during the study period.
The results of this study are similar to those found in randomized controlled trials of SMTs reported in the peer-reviewed literature for LBP  and neck pain.  With our use of a less robust methodology as compared with a clinical trial, one might expect that the direction of bias for our study would be toward a positive treatment effect, and this was indeed the case. However, the magnitude of the effect was not anticipated. Post hoc analyses revealed that treatment outcomes remained clinically important when we stratified by sex, BMI, income, and condition type (acute vs chronic). Closer examination revealed novel data that may be interesting for others to explore further: overweight and low-income clients presented with more pain and worse physical health as compared with their normal-weight and higher-income counterparts.
An inherent limitation of our study, as for any uncontrolled study, is that we have no comparison or control group against which to compare our results. Therefore, we cannot definitively state that the effect observed was caused only by the chiropractic treatment. Other nonspecific effects of treatment (social desirability and attention bias) may completely or partly explain the positive findings. Only with the use of a more robust methodology could the results be more definitive.
The focus of this study was not on examining a specific technique but on investigating the effectiveness of chiropractic treatment as it is delivered in the field (ie, a pragmatic approach). From previous work, we understand the typical chiropractic treatment to entail any combination of SMT, information, specific soft tissue work, massage, mobilization, manual traction, exercise, and individualized advice.  Our chiropractors used all of these treatments for the CHC clients. The mean number of treatments per patient falls within acceptable parameters for the treatment of acute and chronic conditions. 
There were several clinical issues that created difficulties in treating and performing research on the CHC client population. The clients were often illiterate in English and in their mother tongue. The chiropractors also noted some difficulties in obtaining a thorough patient history because of language difficulties and/or traumatic circumstances surrounding the event that led to the patients' MSK condition (eg, torture and abuse). Comprehension of the VAS for pain proved to be difficult for many patients, and the translators employed to translate the English questionnaire into the clients' mother tongue noted comprehension difficulty with some of the aspects of the SF-12v2 and the disability indexes. Furthermore, the method in which the disability indexes assess levels of disability used questions that are less applicable to a low-income population. Specifically, questions on pain when driving and that when reading were not applicable to many clients. These difficulties add to the treatment time. The efficiency of the clinic was hence diminished, which limited the volume of patients who could be seen. Most patients lost to follow-up in this study failed to attend the clinic. Compliance with medications and health-related education/advice, missed attendance, and appointment scheduling difficulties are all common problems in primary health care clinics in CHCs.
Another important clinical issue in CHCs is the prevalence of serious comorbidities. Most CHC clients had coexisting serious medical or mental health problems. In our two clinics, we had clients who were victims of torture or abuse (past or present) and who had dual diagnoses. In the medical clinics at the CHCs, MSK disorders are not usually seen as important issues for medical doctors to deal with because they are not life-threatening. Other pressing health issues, such as diabetes, psychiatric conditions, and respiratory disorders, take higher priority in time-limited patient encounters. However, MSK disorders lead to high levels of disability, lack of employment options, time off work, or protracted time on disability insurance. The presence of a chiropractor as part of the primary health care team provides a treatment option for family physicians to refer to for care of those MSK conditions that are perhaps not as high of a medical priority but critically important to the clients' functioning in society.
In Ontario, chiropractic lies outside of the publicly funded health care system and is primarily accessed by patients with private health insurance coverage or higher household incomes. Including chiropractors in publicly funded primary health care CHC teams helps reduce the burden of chronic MSK pain and disability in those patients of low socioeconomic status who would normally face barriers to accessing chiropractic care. These positive findings should stimulate further, more robust, research into integrating chiropractic care into health centers that serve clients with barriers to health care access.
Canadian populations of low socioeconomic status face barriers to accessing chiropractic care.
Chiropractic care appears to be an effective treatment for patients of low socioeconomic standing.