Preventing progression from chronic to widespread pain and its impact on health-related quality of life: a historical cohort study of osteopathic medical care

Methods

Results

A total of 462 registry participants met the eligibility criteria, including 101 (21.9%) in the osteopathic medical care group (Figure 1). The mean age of participants at baseline was 52.7 ± 13.2 years (range, 22–79 years) and 336 (72.7%) were female. The medical care groups were comparable on many sociodemographic and clinical characteristics at the time of registry enrollment (Table 1). Prior use of spinal manipulation was more often reported in the osteopathic medical care group (68.3%) than in the allopathic medical care group (44.0%) (p<0.001). Other less highly significant group differences involved educational level, cigarette smoking status, heart disease, and use of acupuncture. Osteopathic manipulative treatment was used by 73 (15.8%) participants, possibly used by 179 (38.7%) participants, and never used by 210 (45.5%) participants.

Figure 1:

Flow of participants through the study.

The period prevalence rate of widespread pain was 77 (76.2%) for participants in the osteopathic medical care group, as compared with 315 (87.3%) for participants in the allopathic medical care group (OR, 0.47; 95% CI, 0.27–0.81; p=0.006). The lower prevalence of widespread pain in the osteopathic medical care group persisted after adjustment for age, sex, and the other potential confounders (OR, 0.48; 95% CI, 0.26–0.90; p=0.02). The period prevalence rate of widespread pain was 52 (71.2%) for participants who used OMT, 159 (88.8%) for participants who possibly used OMT, and 181 (86.2%) for participants who never used OMT. There was a lower risk of widespread pain in the group that used OMT vs. the group that never used OMT as a control group (OR, 0.40; 95% CI, 0.21–0.75; p=0.004), but not in the group that possibly used OMT (OR, 1.27; 95% CI, 0.69–2.34; p=0.43). The lower prevalence of widespread pain in the group that used OMT did not persist after adjustment for potential confounders (OR, 0.59; 95% CI, 0.27–1.26; p=0.17).

The osteopathic medical care group reported lower widespread pain severity than the allopathic medical care group (median, 2; interquartile range, 0–4 vs. median, 3; interquartile range, 0–5) (p=0.008) (Figure 2). Correspondingly, the group that used OMT reported lower pain severity (median, 2; interquartile range, 0–5.5) than the groups that possibly used OMT (median, 4; interquartile range, 2–7) and never used OMT (median, 4.5; interquartile range, 2–6) (p=0.02).

Figure 2:

Widespread pain severity according to group. Group comparisons involve the medical care group (A) and whether osteopathic manipulative treatment (OMT) was used (B). The severity score represents the sum of participant responses at five quarterly encounters from baseline through the 12-month follow-up. Higher scores represent more severe widespread pain. A score of 0 indicates that widespread pain was not reported during the study.

The osteopathic medical care group reported better age- and sex-adjusted outcomes for each of the seven dimensions of HRQOL throughout the study (Figure 3). The group differences in age- and sex-adjusted main effects were: mean, 3.29; 95% CI, 1.66–4.92 (p<0.001; d=0.37) for physical function; mean, 2.78; 95% CI, 0.50–5.06 (p=0.02; d=0.22) for anxiety; mean, 2.94; 95% CI, 0.74–5.15 (p=0.009; d=0.24) for depression; mean, 2.36; 95% CI, 0.02–4.71 (p=0.048; d=0.18) for fatigue; mean, 2.96; 95% CI, 1.10–4.81 (p=0.002; d=0.29) for sleep disturbance; mean, 3.77; 95% CI, 1.72–5.82 (p<0.001; d=0.34) for participation in social roles and activities; and mean, 3.16; 95% CI, 1.36–4.96 (p=0.001; d=0.32) for pain interference with activities. These group differences were clinically important for all HRQOL dimensions except fatigue.

Figure 3:

Health-related quality-of-life outcomes according to medical care group. Group comparisons involve physical function (A), anxiety (B), depression (C), fatigue (D), sleep disturbance (E), participation in social roles and activities (F), and pain interference with activities (G). The scores for these dimensions on the Patient-Reported Outcomes Measurement Information System with 29 items were transformed and standardized using the Unites States general population, wherein the mean is 50 and standard deviation is 10. Higher scores represent worse outcomes on each dimension except physical function and participation in social roles and activities. Error bars represent 95% confidence intervals.

The use of OMT was associated with better age- and sex-adjusted outcomes for all HRQOL dimensions except fatigue (Figure 4). The group differences in age- and sex-adjusted main effects for participants who used OMT vs. those who never used OMT were: mean, 4.31; 95% CI, 2.48–6.14 (p<0.001; d=0.56) for physical function; mean, 3.42; 95% CI, 0.86–5.99 (p=0.009; d=0.32) for anxiety; mean, 3.05; 95% CI, 0.57–5.53 (p=0.02; d=0.29) for depression; mean, 1.60; 95% CI, −1.01 to 4.22 (p=0.23; d=0.14) for fatigue; mean, 2.89; 95% CI, 0.81–4.97 (p=0.007; d=0.33) for sleep disturbance; mean, 3.90; 95% CI, 1.62–6.19 (p=0.001; d=0.40) for participation in social roles and activities; and mean, 3.71; 95% CI, 1.69–5.73 (p<0.001; d=0.43) for pain interference with activities. These group differences were statistically significant and clinically important for all HRQOL dimensions except fatigue. The group that possibly used OMT did not report better age- and sex-adjusted outcomes on any of the HRQOL dimensions.

Figure 4:

Health-related quality-of-life outcomes according to osteopathic manipulative treatment (OMT) group. Group comparisons involve physical function (A), anxiety (B), depression (C), fatigue (D), sleep disturbance (E), participation in social roles and activities (F), and pain interference with activities (G). The scores for these dimensions on the Patient-Reported Outcomes Measurement Information System with 29 items were transformed and standardized using the Unites States general population, wherein the mean is 50 and standard deviation is 10. Higher scores represent worse outcomes on each dimension except physical function and participation in social roles and activities. Error bars represent 95% confidence intervals. Pairwise comparisons of participants who used and never used OMT are further presented in the text.

Discussion

This study found that the groups who received osteopathic medical care and who used OMT were both less likely to progress from chronic low back pain to widespread pain over the course of 12 months. Accordingly, both of these groups also reported lower widespread pain severity. These findings align with the view that osteopathic physicians provide a more holistic approach to medical care, including use of OMT when indicated for low back pain [9]. In providing medical care for patients with chronic low back pain, osteopathic physicians may assess and treat such patients more comprehensively rather than focusing only on pain within a limited anatomical location, thereby lowering the risk of widespread pain progression and its impact on HRQOL. Indeed, it has been argued that osteopathic tenets and principles for pain management preceded the widely accepted and heuristic biopsychosocial approach [14]. Proponents of the latter approach now recognize the importance of the physician-patient relationship in offering empathy, encouragement, and hope for patients with chronic pain [15].

The study findings also support the American Osteopathic Association guideline for OMT for patients with low back pain [5]. Therein, it is recommended that osteopathic physicians assess patients to determine if somatic dysfunction is the cause or a contributing factor in the presentation of low back pain. If somatic dysfunction is the cause of low back pain, then OMT should be used to address its impact on the body framework system, including any skeletal, arthrodial, and myofascial structures that may be affected, and their related vascular, lymphatic, and neural elements [16]. If somatic dysfunction is only a contributing factor to low back pain, then an examination for the primary cause should be undertaken so that it may be treated accordingly.

The lower risk of widespread pain observed in the groups receiving osteopathic medical care and using OMT over 12 months was associated with benefits in HRQOL. It is noteworthy that these benefits were observed in all seven dimensions of HRQOL except fatigue. These included benefits relating to anxiety, depression, and sleep disturbance, which are not generally assessed in studies of musculoskeletal disorders, including those specifically involving OMT. Previous research has shown that patients treated by osteopathic physicians report greater physician empathy and better interpersonal manner than patients treated by allopathic physicians, as well as better outcomes relating to back-related functioning [17]. The present findings for anxiety, depression, and sleep disturbance further support the view that osteopathic physicians take a holistic approach that transcends merely focusing on the musculoskeletal aspects of chronic low back pain that are more likely to impact such HRQOL dimensions as physical function, participation in social roles and activities, and pain interference with activities.

This study has several strengths that should be noted. It was conducted within a pain research registry involving a digital research platform that enabled remote data acquisition throughout the 48 contiguous states and District of Columbia using a series of validated research instruments relating to chronic low back pain, including several recommended by the RTF [11]. Only 6.7% of registry participants had missing encounters during the 12 months of follow-up, thereby requiring exclusion from the study. The remaining participants reported complete data, thus obviating the need for imputation of missing data. Participants with physician crossover were excluded to derive more specific estimates of the treatment effects for each of the medical care groups.

The study was limited by using standard case report forms that did not include validated research instruments for widespread pain. The latter may be considered an early or mild stage of fibromyalgia [18]. Clinical criteria for fibromyalgia have been established and modified over the past three decades, including the development of patient self-report instruments for research purposes [19], [20], [21]. Such instruments are not deployed in the registry to avoid an onerous participant reporting burden at each encounter. The simple participant self-report item on widespread pain in the Minimum Dataset for Chronic Low Back Pain used herein has shown promise as a sensitive measure of the early manifestations of fibromyalgia [22]; however, it has limited specificity. Consequently, the registry recently began collecting participant data on fibromyalgia as a comorbid condition using a new item on its case report forms. However, there were an insufficient number of participants who completed this new item to perform meaningful analyses in the present study. Similarly, there were too few participants who were entirely free of widespread pain at the baseline encounter to assemble a suitable inception cohort to measure the incidence rate of widespread pain. The period prevalence rate was thus used as an alternative measure of risk.

Conclusions

The study findings reported herein support the claims that osteopathic physicians practice a more holistic approach to medical care. This was demonstrated through a lower risk of progression from chronic low back pain to widespread pain, lower widespread pain severity, and lesser deficits in HRQOL in the groups that received osteopathic medical care and that used OMT.