Pearson’s chi-square was used when comparing the 3 patient groups by physician performance and patient satisfaction, adjusting for baseline differences. Linear modeling was used to examine the relationship of manual therapy to functional status (Roland-Morris score). Cox proportional hazard modeling was undertaken to identify survival curves of time to functional recovery. In all analyses, standard errors were corrected for any intraclass correlation due to nonindependence of patients seeing the same physician.17
Results
The 13 physicians cared for 120 patients in the observational study and 191 patients in the randomized trial [Figure 1]. In each of the studies very similar numbers of patients were seen by each physician. Within the 2 arms of the randomized trial of manual therapy, baseline characteristics were essentially the same [Table 1].
There were some differences in baseline characteristics between patients in the cohort study and the randomized trial. More patients in the randomized trial (41.4% vs 25%, P=.01) had significantly higher severe baseline dysfunction (Roland-Morris score=16-23) than in the cohort study. The mean baseline Roland Morris score was 10.0 for the cohort study patients compared with 12.5 for the manual therapy study patients (P=.03). There were more patients on workers’ compensation in the cohort study (35%) than in the manual therapy study (16.3%, P=.002), and fewer had been employed in the previous 3 months (80.8% vs 90.0%, P=.02).
Patients in both arms of the randomized manual therapy trial were significantly more satisfied than their counterparts in the earlier cohort study in terms of how their physician gave care in the clinical encounter and whether they received effective advice [Table 2]. Patients participating in the manual therapy trial were also more satisfied with their pain relief, their physicians’ overall treatment of back pain, and their ability to perform activities of daily living. Specific items of clinical performance where differences were noted included: the physician took a detailed history; gave useful advice on pain, preventive measures, sleeping, and sitting strategies; and provided back exercises. There were no differences in patient ratings of the physician’s ability to listen effectively, perform a careful physical examination, and explain the cause of their back pain. There were no differences in general health status between the cohort and manual therapy study patients.
When adjusted for baseline function, the presence of sciatica, duration of pain, employment status, workers’ compensation, and income of more than $20,000, mean functional outcomes measured by Roland-Morris scores at 2 weeks were 8.2 for the patients in the cohort study and 6.7 in the manual therapy trial (P=.03); at 4 weeks mean scores were 7.2 for the cohort and 5.2 for patients in the manual therapy trial (P=.02), and at 8 weeks scores were 6.7 and 3.6, respectively (P=.002). These were clinically significant differences showing that all patients in the clinical trial had lower functional disability levels during an 8-week period than patients of the same physicians in the cohort study.
After controlling for baseline Roland-Morris score, duration of low back pain, sciatica, employment status, workers’ compensation, and income more than $20,000, time to functional recovery reported by the patient (using Cox proportional hazard modeling) between the 3 groups of patients was as follows: (1) manual therapy + enhanced care versus cohort: hazard ratio (HR)=1.16; 95% confidence interval (CI), 0.85-1.58; (2) enhanced care alone versus cohort: HR=1.13; 95% CI, 0.82-1.54; and (3) manual therapy + enhanced care versus enhanced care alone: HR=1.03; 95% CI, 0.75-1.40. None of these HRs were significant [Figure 2].
Discussion
Data from patients of 13 physicians involved in an observational study of back care, followed by a randomized trial of the effect of additional clinical skills developed by hands-on training, provide an unusual opportunity to study patient outcomes and physician performance over time. Similar eligibility and exclusion criteria, data collection methods, and outcome measures were used in both studies, allowing us to directly compare the variables of interest.
After controlling for confounding factors and physician clustering effect, patients in the clinical trial of manual therapy had significantly more baseline dysfunction at the index visit but still recovered more rapidly by self-report. After workshop training for the physicians, the proportion of patients who reported effective evaluation and management of their back problem increased substantially.
There were no differences in the 2 studies in the proportions of patients reporting on how effectively their physician listened to them, explained causation, and discussed occupational issues. These latter activities were not specifically addressed in the training workshop, which concentrated on clinical evaluation, manual techniques, and issues of physical rehabilitation. One would expect that a general placebo effect on patients of the training would increase all parameters of their perceptions of care, so the workshop may have produced specific learning effects on the clinicians. Despite a trend favoring the group receiving care from the “trained” physicians, there were no significant differences in how patients perceived the quality of the physician’s physical examination of their back—an item that was particularly emphasized in the workshops. This aspect of physician performance was already highly rated in the cohort group and may have been less likely to show improvement, given the need to know what constitutes a superior examination technique.