Am J Public Health 2002 (Oct); 92 (10): 1628–1633 ~ FULL TEXT
Hertzman-Miller RP, Morgenstern H, Hurwitz EL, Yu F, Adams AH, Harber P, Kominski GF
Department of Epidemiology,
UCLA School of Public Health,
University of California-Los Angeles,
Los Angeles, CA, USA.
Approximately one third as many back pain patients seek chiropractic care compared to those who seek medical care. In earlier randomized clinical trials, investigators found spinal manipulation to have similar or better rates of patient satisfaction when compared to medical approaches such as physical therapy, McKenzie method and standard medical therapy. This study examined the differences in satisfaction between patients assigned to either medical care or chiropractic care in a managed care organization. In this randomized trial, the chiropractic patients were more satisfied with their back care after 4 weeks of treatment. The researchers concluded that providers in managed care organizations may be able to increase the satisfaction of their low back pain patients by communicating advice and information to patients about their condition and treatment.
OBJECTIVES: This study examined the difference in satisfaction between patients assigned to chiropractic vs medical care for treatment of low back pain in a managed care organization.
METHODS: Satisfaction scores (on a 10–50 scale) after 4 weeks of follow-up were compared among 672 patients randomized to receive medical or chiropractic care.
RESULTS: The mean satisfaction score for chiropractic patients was greater than the score for medical patients (crude difference = 5.5; 95% confidence interval = 4.5, 6.5). Self-care advice and explanation of treatment predicted satisfaction and reduced the estimated difference between chiropractic and medical patients' satisfaction.
CONCLUSIONS: Communication of advice and information to patients with low back pain increases their satisfaction with providers and accounts for much of the difference between chiropractic and medical patients' satisfaction.
From the FULL TEXT Article:
Patient satisfaction is an important component of evaluating care for low back pain, especially because objectively measurable treatment outcomes are largely absent. Among low back pain patients in the United States, about one third as many go to chiropractors as to medical doctors.  In recent decades, the formerly skeptical physician community has been reexamining the chiropractor’s ability to treat low back pain and to achieve high patient satisfaction. [2, 3]
In 3 earlier randomized clinical trials, investigators compared patient satisfaction with spinal manipulation vs medical care or physical therapy for low back pain. The first study concluded that patients were more satisfied with chiropractic care than with physical therapy after 6 weeks.  In the second, patients receiving chiropractic manipulation and patients receiving the McKenzie method of physical therapy had similar levels of satisfaction after 4 weeks.  In the third study, patients receiving osteopathic manipulation and patients receiving standard medical therapy (with similar numbers of visits) had similar levels of satisfaction after 12 weeks. 
Results from observational studies suggest that back pain patients are more satisfied with chiropractic care than with medical care. [7–9] In meta-analyses of clinical outcomes of spinal manipulation for back pain, some researchers have concluded that spinal manipulation is more effective than a placebo,  whereas others have argued that no conclusion can be drawn from existing evidence. 
Predictors of satisfaction with chiropractic care have included total duration of treatment, number of visits, and patient’s perception of improvement.  In more recent studies, predictors of satisfaction with medical therapy for low back pain have included posttreatment pain, disability, and employment status ; coping styles; and baseline expectations of effectiveness.  For these medical patients, the change in pain and disability over the course of treatment did not predict satisfaction. [12, 13]
Results from previous studies suggest that chiropractors’ communication styles and beliefs differ from those of physicians. Chiropractors believe that treatment can prevent continuation or recurrence of low back pain  and that the success of treatment depends on the patient’s understanding of low back pain and its treatment. [15, 16] The extent to which differences in giving advice might account for differences in patient satisfaction has yet to be explored. We know from studies of primary care physicians that providing information  and encouraging patient participation in care  lead to greater patient satisfaction. Thus, in the context of our randomized trial of low back pain treatment, we addressed 3 questions:
(1) whether chiropractic patients are more satisfied than medical patients with their back care;
(2) whether chiropractors communicate more advice and information to their patients than do medical providers; and
(3) whether such differences in communication account for differences in patient satisfaction between chiropractic and medical patients.
We screened 2,355 patients and excluded 886; another 788 declined to participate. Of the 681 patients randomized, 340 were assigned to the 2 medical groups and 341 were assigned to the 2 chiropractic groups. All refusals occurred before treatment group assignment. Complete questionnaire and administrative data from baseline to 4 weeks were available for 672 (99%) of the subjects.
Table 1 shows means and frequency distributions of selected baseline characteristics by assigned provider type. Study patients were well educated and mostly non-Latino White; about half were male. Almost half of study patients reported that their current episode of low back pain had begun more than 1 year prior to study entry and almost 60% had back-related leg pain. In the medical and chiropractic groups, average Roland-Morris disability scores were approximately 11, levels associated in past studies with moderate to severe pain  and some disability at work.  Mental health SF-36 scores averaged about 70, which is similar to the average of scores reported for another population of chronically ill patients. 
Unadjusted Differences Between Assigned Provider Groups
The mean satisfaction score was 30.6 for medical patients and 36.1 for chiropractic patients. Thus, the unadjusted difference in mean satisfaction was 5.5 points (95% confidence interval [CI] = 4.5, 6.5), which is approximately equal to 1 standard deviation in the total sample.
Chiropractic patients reported receiving more self-care advice than did medical patients, were more likely to report receiving an explanation of their treatment, and visited their primary providers more often (Table 2). Of those patients who reported past experience with their assigned treatment, slightly more chiropractic than medical patients reported that the treatment had been beneficial; however, fewer chiropractic patients than medical patients had prior experience with their assigned treatment. Per-visit copayment, visit duration, level of confidence in treatment, average changes in pain and disability in the first 2 weeks, and number of patients who received radiological studies were similar for patients in the 2 groups. No deaths or serious adverse events occurred during the 4–week period.
Explaining the Difference in Satisfaction Between Provider Groups
To explain the difference in satisfaction between provider groups, we first adjusted for the following clinical variables: average pain and low back pain disability scores at baseline, changes in these scores from baseline to 2 weeks, and individual provider effects (see Model 1 in Table 3). According to this model, the estimated difference in satisfaction between chiropractic and medical patients was 5.2 points (95% CI = 2.9, 7.5), which is similar to the unadjusted difference between assigned provider groups.
When we added explanation of treatment and amount of self-care advice as covariates, the estimated satisfaction difference decreased to 3.1 points (95% CI = 1.6, 4.7) (see Model 2 in Table 3). Next, we added confidence in treatment, past benefit from assigned treatment, co-payment, duration and number of visits, and baseline demographic and clinical characteristics (see Model 3 in Table 3). From Model 3, the estimated satisfaction difference between chiropractic and medical patients was 2.5 points (95% CI = 0.7, 4.2).
As shown in Table 3 (see Model 3), factors other than provider group appear to have affected patient satisfaction at 4 weeks. Amount of self-care advice and treatment explanation received was positively associated with satisfaction. Smaller increases in satisfaction were observed for patients who had more provider visits, longer visits, more improvement in low back pain disability, and more confidence in treatment.
We next examined the interactions of self-care advice and treatment explanation with assigned provider group. A fitted model that included the interaction of self-care advice with provider group plus the other covariates in Model 3 (Table 3) yielded an estimated difference in satisfaction between chiropractic and medical patients of 4.0 points for patients who reported receiving 0–1 items of self-care advice, 1.7 for those reporting 2–3 items of advice, and 0.7 for those reporting 4 or more items of advice (Table 4). Similarly, when we examined the interaction of explanation of treatment with provider group, the difference in satisfaction between chiropractic and medical patients was greater for patients who did not report receiving an explanation of treatment than for patients who did report receiving such an explanation (see Table 4). When we modeled the 3–way interaction among both communication variables and provider group, the estimated difference in mean satisfaction scores between chiropractic and medical patients nearly disappeared for patients who received an explanation of their treatment and at least 4 items of self-care advice (adjusted difference = 0.1; 95% CI = –2.6, 2.9).
In this randomized trial, chiropractic patients were more satisfied with their back care providers after 4 weeks of treatment than were medical patients. Although similar results have been reported by others, [4–9] those investigators did not examine the role of other factors in explaining this satisfaction gap.
Most of the covariates we measured did not appear to explain the satisfaction gap. For example, although clinical improvement during the first 2 weeks of follow-up, more and longer visits to the provider, and baseline confidence with the assigned treatment were associated with greater satisfaction at 4 weeks, these variables explained very little of the difference in satisfaction between chiropractic and medical patients. Most of the other covariates were only weakly associated with patient satisfaction and did not contribute at all to an explanation of the satisfaction gap.
By contrast, we found that receipt of self-care advice and explanation of treatment had strong estimated effects on patient satisfaction. These findings are consistent with previous studies that demonstrate associations between the amount of information patients receive and their degree of satisfaction.  When we controlled for amount of self-care advice and treatment explanation received, the estimated difference in satisfaction between chiropractic and medical patients decreased appreciably. Furthermore, the estimated satisfaction gap essentially disappeared among patients who reported receiving an explanation of treatment and at least 4 items of advice from their providers.
Among patients who reported receiving little or no self-care advice, however, chiropractic patients were more satisfied with their providers than were medical patients. One possible explanation for this residual difference is that chiropractors might be perceived as specialists. In previous studies, patient satisfaction has been greater with specialized providers of back care such as orthopedists  and specialized pain clinics  than with generalist care. The hands-on nature of chiropractic treatment may also lead to a greater perception of efficacy and thus to greater satisfaction than medical treatment. A second possibility is that the residual difference might have occurred because patients in the chiropractic group were more likely to be seeing new providers (a “honeymoon effect”). This explanation, however, is not supported by our observation that the estimated satisfaction difference between provider groups did not change appreciably when we controlled for baseline measures of experience with, and perceived past benefit from, the assigned treatment. A third potential explanation is that chiropractors might elicit more confidence from their patients because chiropractors tend to express greater conviction than do medical doctors about the reasons for their patients’ problems and what can be done to help them. This explanation, however, is not supported by our observation that baseline levels of treatment confidence were similar for chiropractic and medical patients with prior experience with those types of providers. A fourth possible explanation for the residual satisfaction gap is that chiropractors might give more detailed physical examinations than do medical providers. Again, this explanation is not supported by our observation that the addition of average visit length to the model did not affect the difference in satisfaction between chiropractic and medical patients.
A limitation of our study is that the provider–patient communication variables were measured by self-report. Results from previous studies have shown that satisfaction is more closely related to the actual amount of information provided than to the amount recalled  and that the association between satisfaction and amount of advice recalled weakens as the actual amount of advice received increases.  Those findings suggest that we may have underestimated the effect of receipt of self-care advice on satisfaction; also, they may partly explain why we observed a residual satisfaction gap among patients who reported receiving at least 4 items of self-care advice from their providers.
Because this study was conducted among privately insured managed care patients within a single group practice who were willing to be randomized, the results may not be generalizable to other settings. Nevertheless, the types of care given by medical and chiropractic providers in this study were typical of those found in other settings in the United States. [7, 16, 25, 26]
We conclude that providers in managed care organizations may be able to increase the satisfaction of their low back pain patients by communicating advice and information to patients about their condition and treatment. Differences in the amount of advice and explanation given by chiropractors and medical providers appear to explain much of the satisfaction gap often reported by chiropractic vs medical patients. There is evidence from other studies that training providers in communication enhances satisfaction among primary care [27, 28] and chronic pain patients.  Giving self-care advice and explaining treatment plans may be part of a helpful or reassuring communication style. Providers who communicate in this way may also demonstrate more concern for their patients as individuals or encourage patients to take a more active role in their own care — characteristics often attributed to chiropractors. [14–16] What we do not know is whether communicating this advice and information to patients will influence the course of their disorders. Further work is needed to determine whether patient satisfaction or related behaviors influence the clinical outcome of low back pain.