Changes in Wellness and Quality of Life During Subluxation-Centered Chiropractic Care

Coinvestigators: Ed Owens, Bob Irwin


Most studies of chiropractic efficacy have been limited to low back pain, neck pain or headaches. The notion that chiropractic may enhance one's life experience if used on an ongoing basis has been largely ignored in the literature. In that sense, chiropractic care, aimed at the removal of vertebral subluxation, may be of benefit to a wider proportion of the population (i.e. 100%), besides those complaining of specific illness or pain. Evidence is needed to justify the use of long-term chiropractic care in a population in which the main goals of care are the advancement of health and human potential rather than the treatment of disease or the alleviation of pain.

Measuring benefits of care, beyond symptomatic relief, has been attempted in a chiropractic setting using tools derived from the social sciences. It has been found that general health, wellness and quality of life are quantifiable, from the patients' perspective. While general health measures have been shown to improve in patients undergoing chiropractic care, this has not been related to wellness or quality of life. A recent instrument developed by Blanks, Schuster, and Dobson seems to be able to access some relationship between the duration of care and wellness in patients undergoing a specific type of chiropractic care. However, this study should be expanded to include other types of chiropractic care and enhanced by the collection of longitudinal, rather than cross-sectional data.

The proposed research will involve the co-administration of the well-established SF-36 general health survey and the Self-Rated Health & Wellness Survey (SRHW) developed by Blanks et al. Surveys will be administered to all new patients in a chiropractic college health center environment. Patients will be recruited regardless of entering complaint, will be cared for by student interns, and will complete follow-up questionnaires at monthly intervals. It is anticipated that as many as 1,200 patients will participate in the study.

Analysis of the data will test the effects of student-administered chiropractic care, aimed at the removal of vertebral subluxation, on patients' general health, wellness and quality of life. Statistical tests will be used to evaluate the reliability and internal validity of the newly developed SRHW, as well as compare its performance with the well-established SF-36. Significant overlaps between the two surveys are expected to be found, as well as unique aspects. For instance, while both surveys ask the patients to rate their physical functioning, only the SF-36 contains questions related to social wellbeing.

The project should be completed within two years, although, as a continuing feature of the college health center, continued data collection could allow better evaluation of patient progress, chiropractic clinical training effectiveness, and the long-term benefits of care.


A. Specific Aims

Chiropractic has made great inroads towards being accepted as an alternative method of care for such common complaints as low back pain, neck pain, and headaches. There is yet a largely untested assertion, though, that routine chiropractic care can enhance wellness and human performance through the correction of vertebral subluxation. In that sense, chiropractic care may be of benefit to a wider proportion of the population (i.e. 100%), rather than just those complaining of specific illness or pain. The notion that chiropractic may enhance oneís life experience if used on an ongoing basis has been largely ignored in the literature. Most studies of chiropractic efficacy have been limited to low back or neck pain or headaches.

The beneficial effects of short-term chiropractic care on general health have been demonstrated using the RAND SF-36 in several studies, but these have shown the effects of care on health as it relates to alleviation of patient complaints. Evidence is needed to justify the use of long-term chiropractic care in a population in which the main goals of care are the advancement of health and human potential rather than the treatment of disease or the alleviation of pain. The principle objective of this study is to evaluate the quality of life and well being, ranging beyond symptom alleviation and illness prevention, expressed in subjects that receive ongoing, vertebral subluxation-centered chiropractic care.

Two survey instruments will be incorporated to evaluate perceived health and wellbeing. This cohort study will use the SF-36 Health and Wellness surveys to assess the effect of specific full-spine chiropractic care. The specific aims of this study are to: (1) show how chiropractic care significantly improves self-perceived wellness and functioning as measured by the SF-36 Health and Wellness Surveys; (2) explore the relationship between the Wellness Survey and the SF-36 Health Survey to determine the external validity of the Wellness survey; (3) validate the Wellness Survey internally by checking the reliability of each dimension; and (4) determine if changes in wellness are related to patientsí choice to remain with ongoing chiropractic care.

This study is designed to document the effectiveness of the care based on certain wellness dimensions and to meet the needs of outcome assessment in chiropractic care. The expectancy is that the survey instruments will provide a way to evaluate the perceived wellness of vertebral subluxation-centered chiropractic care. The duration of care is expected to be directly related to the wellness and quality of life scores, when other factors known to effect quality of life are controlled.

B. Background and Significance

The efforts of the Medical Outcomes Study have produced a wide array of survey instruments that assess various aspects of general health and quality of life (Ware and Sherbourne, 1992). The most popular of these, the RAND SF-36, has been applied in the chiropractic setting and found to be sensitive to changes in general health occurring during chiropractic care in a practice environment (Hawk and Morter, 1995, Hawk, 1995, Wallace, Dickholtz, and Woodfield, 1996, Hoiriis, Owens, and Pfleger, 1997, Dickholtz and Woodfield, 1998, Hoiriis, Owens, and Burd, 1998). The studies have looked at the short-term outcomes of chiropractic care, particularly in relation to the alleviation of entering complaints.

While the SF-36 has a wide history of use and is well validated in several populations exhibiting clinical conditions, it may suffer from a "ceiling" effect when used in essentially healthy populations (Blanks, Schuster and Dobson, 1997). More recently, Blanks, Schuster and Dobson have developed and tested a new instrument aimed more specifically at wellness and quality of life (Blanks, Schuster and Dobson, 1997).

The "self-rated health, wellness and quality of life" survey (SRHW) contains two parts, a newly developed wellness survey consisting of 40 items, and a 14-item quality of life questionnaire developed by Woodruff and Conway (Woodruff and Conway, 1992). The wellness survey itself has subscales "formulated to reflect aspects of the broad WHO definition of health; including the domains of physical and mental/emotional state and inter/intra-personal life enjoyment indicative of physical, mental and social psychological well-being" (Blanks, Schuster, and Dobson, 1997).

Blanks, Schuster and Dobson performed a cross-sectional study with the cooperation of practitioners using a particular chiropractic technique. In a population of 2,800 chiropractic patients, the examiners found the instrument to rate highly in internal validity and sensitivity to change. In order to detect sensitivity to change, the authors had patients provide elaborate responses describing both their status, as well as their recollection of their status before beginning chiropractic care.

As a further test of the usefulness of this new SRHW instrument, the SF-36 and the SRHW will be co-administered in a full-spine chiropractic clinic setting and track changes over time. The study should be a significant contribution to the validation of SRHW and will be useful to policy makers in decisions regarding the value of continued chiropractic care in the absence of symptoms. There is a strong institutional commitment on the part of Sherman College, with its vertebral subluxation-centered chiropractic curriculum, to see this project completed.


C. Research Methods & Design


The survey instrument in this study has three distinct elements. The first characterizes the sample tested in the study, reporting such data as demographics, length of time under chiropractic care and general health and health care information. The second section consists of the Medical Outcomes Study 36-Item Short Form Health Survey (SF-36) (Ware). The third section is composed of 55 "wellness" items to measure health improvement in a global, non-symptomatic sense (Blanks, Schuster and Dobson, 1997).

The SF-36 is an amalgamation of items from several different health assessment instruments (Ware, 1993). It measures eight different aspects of health: (1) physical functioning, (2) role limitations due to physical health problems, (3) bodily pain, (4) general health, (5) vitality (energy/fatigue), (6) social functioning, (7) role limitations due to emotional problems and (8) mental health (psychological distress and psychological well being). The number of items in each component ranges from two to ten. The scales have been well validated across many studies.

The self-rated wellness scale (Blanks, Schuster, & Dobson, 1996) will be used to measure the outcomes in this study, based on the preventive notion of "wellness" rather than the allopathic alleviation of conditions (McDowell, J., Newell, C., 1996).

The Blanks et al. study developed this survey to more adequately measure the notion of health as defined by the World Health Organization, "a state of complete physical, mental, and social well-being, and not merely the absence of disease or infirmity." The Blanks et al. study accessed the application of a specific package of chiropractic techniques called "Network Spinal Analysis" as the independent variable. Network Spinal Analysis strives to improve overall well being, in contrast to treating a specific condition or disease, as does most medical and chiropractic care. Similarly, full-spine chiropractic care is also designed to enhance overall well being, rather than disease or condition treatment and will be the technique used in this study.

The notion in the Blanks et al study that randomized clinical trials do not adequately explore the wellness paradigm, because of the limited nature of the dependent variables used (normally the reduction in the condition or disease state), is a notion that is in accordance with the paradigm in this study. Broad-based surveys provide the best opportunity to evaluate the efficacy of techniques that profess to add to overall wellness rather than obviate a symptom or cure a disease.

Data Collection

1. Subjects

    1. Selection: 25 subjects per week who report good overall health and no prior chiropractic care.
    2. Inclusion Criteria: Male and female, between the ages of 18 and 59, will be recruited from the community at large.
    3. Exclusion Criteria: Individuals who are not suitable for chiropractic care due to findings in the entrance exam will be excluded. Individuals who do not comply with the written informed consent form will also be excluded.
  1. Survey Administration

All the new patients that begin care are given a new patient orientation session to inform them of the kind of care they will receive. During this orientation, the subject will be interviewed for inclusion and offered the opportunity to participate in this research project. Those who agree to the conditions of the consent form, will complete the SF-36 and the SRHW survey instruments at that time [see appendix].

At monthly intervals thereafter, the patientsí intern will be contacted and informed that it is time to distribute the survey instruments again. This pattern of data collection will continue for the first six months of care and then every six months thereafter.


Data Analysis

Data analysis has three objectives in this study. First, this study will contribute to the understanding of the psychometric scale properties of the Blanks et al. wellness measure. Second, this study will compare and contrast the Blanks et al. measure with the better-established SF-36 scale in order to determine areas of overlap and independence. Finally, statistical analysis will be used to determine both the statistical significance and effect size of hypothesized relationships.

Psychometric Properties of the Wellness Measure. Based on the limited testing of the Blanks et al. wellness survey instrument, a three-step process will be performed on the data collected in this study. Following well-accepted psychometric scale assessment methodology (DeVellis, RF. 1991), all 55 items contained in the wellness survey will be combined into one principal components factor analysis. Blanks et al. posit the existence of three separate dimensions of wellness within these 55 items; this proposed study will further test this assertion. To account for the possible existence of dependence among factors (Blanks et al. note correlations among the dimensions ranging from .34 to .74), both varimax and orthogonal rotations will be applied to the data. Decisions rules for item inclusion will follow well-accepted protocols (DeVellis, 1991). Only factors with eigenvalues greater than 1.0 will be considered in the analysis. Items must load greater than .40 on any one factor, and not load greater than .30 on any other factor.

The second step in data analysis of the wellness instrument will be a confirmatory factor analysis to verify the robustness of the latent variable structure of the data using AMOS (Analysis of Moment Structures) software (Arbuckle, JL. 1997). In line with standard structural equation modeling methodology, chi-square analysis will be used to assess how well the data fits a normal distribution.

The final step in internal validation of the wellness instrument will be a reliability analysis of the items within each of the three dimensions. Following standard reliability analysis, Cronbach's alpha will be used for this purpose (Carmines, EG, Zeller, RA. 1979). Any component that has an alpha of .70 or less will be dropped from the analysis. If items can be dropped from the analysis increasing the alpha to .70 or above, the dimension will be retained in the analysis (less the undesirable items). If no combination of items has a Cronbach alpha of at least .70, that dimension will be dropped from the analysis.

Comparison of SF-36 and Wellness Instruments. In order to compare these two surveys, simple bivariate correlation analysis will be used. Correlation statistics for each dimension of the two scales will be generated. By evaluating these, assertions about the overlap and independence of measurement of the various dimensions will be explored.

Hypothesis-Testing. As the last step in data analysis, analysis of variance (ANOVA) will be used to assess the impact of the six months of chiropractic care on the outcome variables. This statistic compares variation over time with variation within each period; it allows researchers to calculate a probability that changes occurring over time are due to chance.

To further explore the relationship between the application of chiropractic care and wellness, paired t-tests will be performed for all study participants at t0 and after six months of care.

In both the ANOVA analysis and the paired t-tests, care will be taken to include study participants who discontinued care during the course of the study. This is necessary because of the threat of reverse causality; without this safeguard, it could be argued that a positive relationship between time under care and wellness improvement was simply the result of removal of people with no improvement from the study data.



  1. Human Subjects
  2. Every effort will be made to maintain the confidentiality of the information gathered from the subjects. The patientsí records will be identified by a number assigned in the health center. A consent form will be provided with the surveys and questionnaires describing the scope and importance of the study along with assurance of confidentiality of the data, specific instructions on filling out the forms, and a toll-free number to call for additional information (see appendix).

  3. Literature Cited