J Manipulative Physiol Ther 2000 (Jan); 23 (1): 1–9 ~ FULL TEXT
Ronald L. Rupert, DC
OBJECTIVE: To investigate the primary care, health promotion activities associated with what has historically been called "maintenance care" (MC) as used in the practice of chiropractic in the United States. This includes issues such as investigating the purpose of MC, what conditions and patient populations it best serves, how frequently it is required, what therapeutic interventions constitute MC, how often it is recommended, and what percent of patient visits are for prevention and health promotion services. It also investigates the economic impact of these services.
DESIGN: Postal survey of a randomized sample of practicing US chiropractors. The questionnaire was structured with a 5-point ordinal Likert scale (28 questions) and brief fill-in questionnaire (12 questions). The 40-question survey was mailed to 1500 chiropractors selected at random from a pool of chiropractors with active practices in the United States. The National Directory of Chiropractic database was the source of actively practicing chiropractors from which doctor selection was made. The sample was derived by using the last numbers composing the zip codes assigned by the US Postal Service. This sampling method assured potential inclusion of chiropractors from all 50 states, from rural areas and large cities, and assured a sample weighting based on population density that might not have been afforded by a simple random sample.
RESULTS: Six hundred and fifty-eight (44%) of the questionnaires were completed and returned. US chiropractors agreed or strongly agreed that the purpose of MC was to optimize health (90%), prevent conditions from developing (88%), provide palliative care (86%), and minimize recurrence or exacerbations (95%). MC was viewed as helpful in preventing both musculoskeletal and visceral health problems. There was strong agreement that the therapeutic composition of MC placed virtually equal weight on exercise (96%) and adjustments/manipulation (97%) and that other interventions, including dietary recommendations (93%) and patient education about lifestyle changes (84%), shared a high level of importance. Seventy-nine percent of chiropractic patients have MC recommended to them and nearly half of those (34%) comply. The average number of recommended MC visits was 14.4 visits per year, and the total revenue represents an estimated 23% of practice income.
CONCLUSIONS: Despite educational, philosophic, and political differences, US chiropractors come to a consensus about the purpose and composition of MC. Not withstanding the absence of scientific support, they believe that it is of value to all age groups and a variety of conditions from stress to musculoskeletal and visceral conditions. This strong belief in the preventive and health promotion value of MC motivates them to recommend this care to most patients. This, in turn, results in a high level of preventive services and income averaging an estimated $50,000 per chiropractic practice in 1994. The data suggest that the amount of services and income generated by preventive and health-promoting services may be second only to those from the treatment of low-back pain. The response from this survey also suggests that the level of primary care, health promotion and prevention activities of chiropractors surpasses that of other physicians.
From the Full-Text Article:
Postal surveys have inherent weaknesses but are a well-established form of biomedical research. One of the specific weaknesses in this study involves requesting chiropractors to provide the number of new patients per month, the percentage of income derived from MC, and other data that are not based on accurate counts and calculations but on estimates. In addition, the response rate (44%), although disappointing, was relatively strong for a chiropractic postal survey. Surveys within the profession rarely result in as much as a 50% response rate; previous survey response rates related to chiropractic and prevention have ranged from 22% to 65%. [7, 12] A control number was assigned to each questionnaire to facilitate follow-up of nonrespondents. However, this did not prove effective because many doctors who did respond either obliterated, marked out, or actually tore off the number from the form to ensure anonymity. With the accuracy of written follow-up compromised, a selected follow-up was made by telephone. Eighty-five doctors for whom there was no record of a completed questionnaire were called and asked  if they completed the survey,  if they did not respond, why, and  if they used MC in their practice. Doctors indicated that the most common reason for nonparticipation was that they were too busy. The majority of nonrespondents also reported that they used some form of MC in their practices.
A review of the demographics of chiropractors who completed and returned questionnaires for this study did not vary significantly from other large contemporary surveys, with the exception of sex. The annual survey conducted in 1995 by the American Chiropractic Association reflected a sex mix within the profession of 88% men and 12% women.  The response to this MC study and previous prevention-related research conducted by Hawk and Dusio  both had a slightly higher percentage of female respondents than the national American Chiropractic Association survey (83% male and 17% female; 81% male and 19% female, respectively). Hawk and Dusio  indicated that the larger number of female respondents may reflect a bias.  However, a recent medical study suggests that female physicians may have a greater interest in ention activities than male physicians.  This same phenomenon may in fact be operative within chiropractic and may account for the greater participation of women in this prevention-related survey. The average age of respondents in this study was 41 years compared with an average age of 44 years in the 1995 American Chiropractic Association survey. 
Prevalence of use
Previous work outside the United States suggests that the use of MC accounts for a significant amount of services rendered by chiropractors. In England, Breen  noted that after management for conditions like low-back pain, “39% of patients made further visits for maintenance treatment.” The Jamison  study of Australian chiropractors found that 62% performed MC on up to one third of their patients; 32% performed MC on 34% to 66% of their patients; and 6% performed MC on 67% to 100% of their patients.  This study attempted to address the same issues for chiropractors in the United States. Chiropractors were asked to provide the percentage of their patient load that received MC; the mean response was 34.4%. This suggests that a large percentage of chiropractic care given around the world is directed at prevention and health promotion. Shekelle  reported that 42.1% of patient visits to chiropractors were for low-back symptoms followed by 10.3% for neck/face symptoms. However, if as this study suggests, 34.4% of patient visits are for the purpose of MC, then preventive services may be the second most common reason for visits to a chiropractor. In addition to this high percentage of patients receiving MC, a much higher number, 78.7% of US patients, receive the recommendation to continue with preventive MC. This strong recommendation to receive preventive services suggests attitudes that are similar to Australian chiropractors: 41% asserted that everybody would benefit from such care, 38% believed that most would benefit, and 14% believed that some patients would benefit. 
Despite the emphasis by the US Government on initiatives such as Healthy People 2000,
 the medical community continues to face many obstacles to providing preventive and health promotion services. [25-28] With the use of MC to the extent described in this study, the chiropractic physician appears to place more emphasis on, derive more income from, and perhaps commit more patient time to prevention and health promotion purposes than many other health care professionals.
Another Australian study by Webb and Leboeuf
 found that there was a higher level of MC performed by doctors who had a lower number of new patients per month. The current research confirmed similar practice patterns (although number of MC visits was not ascertained) with a statistically significant inverse relation and correlation (P < .05) between the number of new patients per month and the practice income generated from MC.
Economics of MC
In conjunction with the high percentage of patients who have been recommended for MC and the nearly half that comply, there also is a relatively high financial impact with an average 22.9% of all chiropractic income in the United States generated from these services. Based on an annual gross income of $225,783,20 MC accounts for an average annual income of $51,930 per practice. When the 22.9% is viewed in the context of the total revenues of all chiropractors,
 this would equate to $48 million in MC services delivered to US citizens during 1994.
It was not possible to be more specific about how patients paid for MC because of the necessity for reasonable brevity of professional surveys. Because most health insurance policies will not reimburse policyholders for health promotion services, future research should explore the methods of payment for MC.
A few authors have stated or implied that there are serious ethical issues with maintenance programs and that there is an inappropriate financial motive for what is termed “spurious” services.
[22, 30] Homola
 states that “It is unfair to patients to allow them to believe that they must have regular spinal adjustments in order to stay healthy.” Two findings from this survey suggest appropriate financial motive to MC services. First, the majority of the respondents (98%) agree that MC is of value for prevention and promoting the health of their patients. Twelve respondents, representing only 1.9% of the responding population, indicated that they never recommended MC. This consensus about the value of MC is remarkable considering the historical disagreement within the profession about so many other issues. In addition to the 98.1% of chiropractors recommending MC to their patients, 98% also agreed with at least 1 of the 6 questions describing the possible health benefits of MC. Chiropractors believe in the value of MC (98%) and therefore 98% recommend its use to their patients. Recommending the use of a procedure without belief in its value would suggest possible financial or other inappropriate motives, but this is not the case with MC. Secondly, 70.5% of chiropractors responded that they did not agree that MC was used for financial gain. Only 8.9% strongly agreed that MC was overused. The belief that MC was overused was significantly negatively correlated (P < .01), with both recommending MC to patients and the belief in the value of MC. Thus doctors who did not believe there was therapeutic value to MC (and did not or rarely recommended its use) were the ones who believed MC might be overused for financial gain.
This survey did find a significant inverse relation (P < .05) between the number of new patients per month and practice income from MC. However, the recommendation to receive MC was not related to practice income. There was also no correlation between income from MC and the doctors' belief that MC was of value in promoting health. These facts suggest that despite the number of new patients per month, chiropractors believe in the value of MC regardless of whether or not they are actually deriving income from MC services in their practices. It is possible that those chiropractors with lower patient loads are simply able to dedicate more time, and thus a higher percentage of their income is generated from MC services. Chiropractors, like all health care providers, must meet financial obligations and must charge for their services. It is reasonable to expect that they would focus on services for which they can expect reimbursement. MC, which is not covered in the United States by most health insurance, Medicare, or worker's compensation programs, is not one of those services. Therefore chiropractors with high volumes of patients with low-back pain and other reimbursable conditions might be less likely to spend as much time on services for which reimbursement is difficult, such as MC.
Composition of MC
Previously, no data existed that described the therapeutic constituents of MC. Recently, there has been speculation by authors that chiropractors “keep people well through spinal adjustments”  and that diet, exercise, lifestyle changes, and other prevention-directed activities are not part of the profession's prevention efforts. This view appears inaccurate because this study depicts the preventive MC activities of chiropractors as a combination of interventions that rely heavily on exercise, nutrition, and lifestyle changes. Although most doctors (96.7%) responding did agree that spinal manipulation was an essential component of preventive MC services, the respondents also agreed that exercise was an equally important component (96.1%), followed closely by proper eating (92.8%), patient education (83.6%), and vitamin and supplement usage (67.1%).
Value of maintenance care
To ensure a response from field doctors, the questionnaire was only 1 page. Because of the short length of the questionnaire, there were only 4 age groups of patients listed: children, adolescents, adults, and the aged. The survey described a consensus about the value of MC for all 4 patient groups. This was a consistent response, considering the high percentage of patients recommended to receive MC. In addition, there is a prevalent belief that preventive MC services are helpful in a variety of visceral conditions and musculoskeletal problems. Because of the eclectic nature of the therapies used in MC and because it is standard medical practice to make exercise, nutritional, and other recommendations for many visceral problems, it is not surprising that chiropractors would also address these conditions. It was beyond the scope of this initial study to ascertain to what extent chiropractors believe specific visceral and musculoskeletal conditions benefit specific therapeutic components of MC. Five different purposes for MC were given with this survey. Relatively strong agreement was found for all but 1 (ie, the prevention of subluxation). Slightly more than half of chiropractors believed MC was valuable for this purpose. This response raises questions about the belief system of chiropractors because it relates to prevention and the subluxation concept. If MC cannot prevent subluxation, how is it prevented? Future studies should be directed at exploring wellness and prevention in the context of subluxation.
The 658 doctors who responded to the survey were relatively unaware of the scarce research that supports the use of MC. Forty percent believed that “chiropractic research adequately supports the value of MC” and <7% strongly disagreed with that statement. This misconception exists despite the fact that the deficiency in supporting research has been brought to the profession's attention on many occasions by both the medical community and those involved in chiropractic research.
[32-35] The survey did establish that the overwhelming majority (93.4%) of the profession agreed that there was a need for further research. The research issue questions the education of chiropractors as it relates to MC. Future research should be directed at why there is such a strong belief in the value of the spinal manipulation component of MC among both new and established chiropractors. In what manner is this subject addressed in chiropractic colleges and to what extent does practice experience have an impact on the belief in MC? One reason why chiropractors may believe that adequate research exists is simply because, as this survey suggests, MC includes a wide variety of well-researched health promotion components, including exercise, food supplementation, and diet.
The chiropractic profession has had a historic interest in and emphasis on health promotion and prevention, often referred to as MC. The literature to date consists primarily of individual opinions that, based on this work, have often misrepresented the motivation, therapeutic components, extent of use, and other elements of MC. The respondents to this survey, like their European and Australian counterparts, strongly believe in the preventive and health-promoting merits of periodic visits for MC. MC is believed to benefit patients of all ages for a wide variety of visceral and musculoskeletal conditions. Belief in the efficacy of MC translates into a high rate of recommendation to patients and a substantial economic impact on chiropractic practice. Although chiropractors with low new patient traffic tended to recommend MC services more often, both chiropractors with low and high new patient traffic believed that MC was valuable for promoting patient health. The recommendation that patients receive MC was also not related to practice income from MC. Therefore the belief in the value of MC appears to be motivated by its potential value to the patient and not for financial gain as some have suggested. Chiropractors concur that MC is not simply administering periodic manipulative treatments but rather that exercise, nutritional, and lifestyle recommendations are equal or nearly equal in importance.