Characterizing the use of osteopathic manipulative medicine in the obstetric population by trimester and indications for use

Methods

Obstetrical care providers from Portland, Augusta, and Waterville, Maine, were eligible for inclusion in this cross-sectional study if they had obstetrics privileges at one of two main delivery centers in Southern and Central Maine. Providers included attending and resident physicians, as well as family nurse practitioners (FNPs) and certified nurse midwives (CNMs). Both delivery centers were located at training hospitals: one with a dually-accredited (American Osteopathic Association/Accreditation Council for Graduate Medical Education [ACGME]) family medicine residency program, and one with ACGME-accredited residency programs for both family medicine and obstetrics/gynecology. The study was determined to be exempt by the institutional review boards at both Maine Medical Center and Maine General Medical Center.

An anonymous, 43-item survey, presented in English, was emailed to 172 eligible providers via an encrypted database system in January 2018. Follow-up email reminders were sent weekly for three weeks (Appendix A). Of the 43 questions, 23 were on a five-point Likert scale (one regarding familiarity with OMM [1=Slightly, 5=Extremely], five regarding use of or referral to OMM during pregnancy periods [1=Never, 5=Always], 12 regarding likelihood of using OMM for a specific indication [1=Extremely unlikely, 5=Extremely likely] five regarding perceived barriers of OMM use [1=Extreme barrier, 5=Not a barrier]), eight were true/false questions, one was open-ended, and the remaining nine questions were demographic.

The survey was developed internally, in collaboration with local OMM and obstetric providers, because we were unable to identify any published, validated surveys targeting the specific questions of this study. Questions about the use of OMM for specific indications were developed based on findings from prior studies^{1,2,3,4,5,13,14} identifying potential uses of OMM in pregnancy; these same indications were assessed for each trimester as follows: nausea, headaches, constipation, peripheral edema, carpal tunnel syndrome, De Quervain’s tenosynovitis, low back pain, pelvic girdle pain, anxiety, nasal congestion, coccydynia, intrapartum pain, and hemorrhoids. Questions about OMM knowledge were based on common misconceptions that nonosteopathic providers may have about OMM.^15,16 We included questions to address perceived barriers to the use of OMM in patient care, followed by one open-ended question inquiring about the types of adjunctive treatment used by the practitioner.

Demographic data were collected categorically; practice factors were included if they were relevant to planned data stratification, such as training type and provider specialty, or if they had known associations with use of OMM or adjunctive treatment.^15,16,17

Results

Of 172 providers to whom the survey was distributed, 73 (42%) responded (Figure 1). Due to the lower response rate of non-physician providers (n=4) compared with physician providers, we limited our analysis to the 69 physicians who completed the survey, resulting in a physician response rate of 40%. Of the 69 physicians who responded, not all questions were answered. We adjust the n for those unanswered questions in our presentation of the data accordingly. The characteristics of the physician respondents are summarized in Table 1. Of the 69 physicians who completed the survey, 53 (76.8%) were women, 16 (23.2%) were men, 50 (72.5%) were allopathic physicians, 40 (57.9%) practiced family medicine, and 40 (57.9%) worked in the context of a residency program. Experience levels varied from current resident (28 [40.6%]) to more than 20 years in practice (11 [15.9%]). Although most physicians (47 [68.1%]) reported being “moderately/extremely familiar” with OMM, this differed by training and by specialty. Twenty-eight of 49 (57.1%) allopathic physicians were “moderately/extremely familiar” with OMM compared with 19 osteopathic physicians (100%; p<0.001). (One provider did not answer this question; therefore, that person was excluded from this questions analysis, leaving a total of 49 responses.) Additionally, 31 of 40 (77.5%) family medicine physicians were “moderately/extremely familiar” with OMM, compared with 15 of 28 (53.5%) obstetrics and gynecology physicians (not significant, p=0.10). Medical training, however, differed by specialty; 15 of 40 (37.5%) family medicine physicians had osteopathic training compared with three of 28 (10.7%) obstetrics and gynecology physicians.

Figure 1:

Survey distribution and responses.

Out of 60 respondents who answered the question, 59 (98.3%) providers agreed that OMM is useful for helping neuromusculoskeletal pain related to pregnancy; actual OMM usage was less frequent, however. Overall, 50 of 68 (73.5%) providers reported that they “often/always” used OMM or referred patients to an OMM specialist at some point during pregnancy or postpartum. This rate varied slightly, though not significantly, with provider training; 34 of 49 (69.4%) allopathic physicians reported any use of, or referral to, OMM during pregnancy and postpartum, compared with 16 of 19 (84.2%) osteopathic physicians (p=0.36). Table 2 summarizes providers’ reported use of and referral to, OMM at different stages of pregnancy, both overall and after stratification by training. OMM use and referral increased monotonically with trimester. Of the 67 physicians who responded, 19 (27.5%) reported that they “often/always” used, or referred to, OMM in the first trimester, 26 (38.2%) in the second trimester, and 35 (51.5%) in the third trimester. This same trend was seen among both osteopathic and allopathic physicians. Use of, or referral to, OMM was least frequent intrapartum (“often/always”: eight of 67; 11.9%) and most frequent postpartum (“often/always”: 41 of 67; 60.3%). At each stage of pregnancy, OMM usage was higher among osteopathic physicians than allopathic physicians; this was significant in the first trimester (p=0.017) and third trimester (p=0.048). The discrepancy was largest for the intrapartum period, with two of 48 (4.2%) allopathic physicians “often/always” using, or referring to, OMM, compared with six of 19 (31.6%) osteopathic physicians (p=0.003). A similar trend was seen when data were stratified by specialty, with higher rates of OMM usage among family medicine physicians than among obstetrics and gynecology physicians at all stages of pregnancy (Appendix B).

Table 3 summarizes physicians’ responses to questions about their use of, and referral to, OMM for common conditions occurring during pregnancy. Among 69 physicians, OMM was used most frequently during pregnancy for four pain-related conditions associated with the axial skeleton (low back, 67 [97.1%]; pelvis, 65 [94.2%]; coccyx, 50 [72.5%]; and head, 49 [71%]). There was no significant difference in usage rates between osteopathic and allopathic physicians for these conditions (Table 3, p>0.05). For all other listed conditions, there was significantly higher usage of OMM among osteopathic physicians. Musculoskeletal conditions such as carpal tunnel syndrome (31 [44.9%]; p=0.008) and De Quervain tenosynovitis (26 [37.7%]; p<0.001) had intermediate usage, while OMM was less frequently used for visceral or lymphatic symptoms such as nausea (10 [14.5%]) or peripheral edema (18 [26.1%]). Similar findings were observed when data were stratified by specialty, with higher rates of use for most conditions cited by family medicine providers (Appendix B).

To explore barriers to the use of OMM for pregnant patients, we used data only from physicians who gave a definitive response to a given question; those who did not answer the question or who reported that they were “unsure” were excluded. Access to OMM was the largest perceived barrier to use, with 45 of 66 physicians (68.2%) reporting some extent of an access as a barrier (Table 4). In contrast, the least frequently-reported barrier by physicians (22/63; 34.9%) was working in a setting where use of, or referral to, OMM was not part of routine practice. There was no significant difference detected between osteopathic and allopathic physicians in their perception of routine practice patterns (seven/17 [41.2%], and 15/46 [32.6%], respectively) or patient compliance (12/17 [7.6%], and 24/48 [50%], respectively) as barriers to OMM use. In contrast, compared with their osteopathic counterparts, allopathic physicians more frequently cited barriers to OMM use as follows: access to OMM (38/49 [77.6%] vs. seven/17 [41.2%]; p=0.013); cost/insurance (35/53 [66%] vs. seven/15 [46.7%]; p=0.040); and referrals (30/47 [63.8%] vs. two/16 [12.5%]; p=0.001). Additionally, many participants, osteopathic and allopathic physicians alike, noted “time” as a barrier to use in the comments section.

Discussion

Use of OMM was highest among all providers in the third trimester and postpartum period, with the lowest overall use during the first trimester and intrapartum period. Our data further revealed that osteopathic physicians were more likely to use OMM during all trimesters, and intrapartum, compared with allopathic physicians. Both allopathic and osteopathic physicians were equally likely to use and refer to OMM postpartum.

Each stage of pregnancy carries unique indications for OMM use because of various physiologic changes taking place.^13,14 For instance, in the first trimester, morning sickness is a common complaint, thought secondary to increased progesterone levels.¹⁸ Common presenting problems of the second trimester include sciatica, as the uterus begins to grow out of the pelvis and increases the axial strain on the lumbar spine and sacrum; round ligament pain, which may correspond to anterior lumbar counterstrain points or pelvic dysfunction; and carpal tunnel syndrome, resulting from localized edema, which occurs more commonly in women with preeclampsia and hypertension.¹⁸ One confounding factor to consider may be that patients with pregnancy-related complaints do not present as frequently during the early trimesters. A study exploring the time periods when patients present and when treatment is initiated would provide more insight into the data presented by our current study. For instance, the PROMOTE study¹⁹ revealed that OMM plus usual OB care can halt back-specific dysfunction when compared with usual OB care alone.^1,20 Future studies could also assess whether initiation of OMM during the first trimester would help halt further deterioration in subsequent trimesters for pre-existing back pain.

Studies targeting the use of OMM during the intrapartum period are also needed. One systematic review⁵ suggested decreased levels of pain during labor and delivery and decreased use of analgesia among patients receiving OMM during labor. Even more compelling are shortened labor duration times, with applied OMT during the intrapartum period, as demonstrated by Martingano et al.,⁷ Hart,⁸ and Whiting.⁹ While a study performed by Hensel et al.¹² reported an increase in labor duration, compared with the prior studies,^7,8,9 labor duration was not reported in terms of hours and minutes due to notable discrepancies found in the medical records among multiple history taker; labor duration was instead defined as precipitous (<3 hours) or prolonged labor (>20 hours). Further, in Hensel et al.,¹² OMT was not performed by the same physician who managed the labor and delivery, unlike other studies.^7,8,9 Future research specifically targeting larger study cohorts could prove useful in the management of labor and delivery ongoing.

Our study also identified areas of decreased utilization when assessing specific indications for use. Although osteopathic physicians were more likely to use and refer to OMM for all indications compared with allopathic physicians, both groups cited musculoskeletal complaints as the highest indication for use and referral. This finding is further supported by a study²¹ that revealed OMT is most frequently directed at the musculoskeletal system (51.5%), and that OMT was less frequently used for other conditions including edema (0.14%), hemorrhoids (0.5%), constipation (0.18%), and GERD (0.14%). This same study cited pregnancy as accounting for only 0.5% of treated conditions.²¹

The decreased use of OMM for visceral and lymphatic complaints demonstrated by our study, along with increased use for musculoskeletal conditions, appears consistent with the breadth of literature supporting OMM use for lower back pain and pelvic girdle pain in the obstetric population. Given that studies have shown a benefit for visceral and lymphatic treatments outside of pregnancy,^22,23 we conclude that these treatments would also benefit the obstetric population. Targeting future studies toward pregnant patients and enhancing education around the varied indications for OMM use could serve as a nidus for further research efforts.

We also observed the trend that family medicine physicians were more likely than obstetrics physicians to use and refer to OMM during the third trimester and intrapartum periods, and for non-musculoskeletal conditions. However, the incidence of osteopathic training was much higher among the family medicine physician cohort (37.5% vs. 10.7% in obstetrics physicians), which may explain this finding. Regardless, the trend is similar to a previous study,²⁴ which reported that 69.9% of family medicine physicians used or referred to OMM on 5% or more of their patients, while only 31.3% of specialists did. While our study supports the evidence that family medicine physicians are more likely to use and refer to OMM, a larger cohort study would be necessary to examine the effects of specialty on OMM use, independent of medical training type.

The highest perceived barriers to OMM use cited among allopathic respondents were access to care, cost, and familiarity with indications for referral. Several respondents listed in the comments section that time is a barrier to use. This disclosure is supported by a previous study²⁴ comprised solely of osteopathic physicians, in which 62% of respondents cited time constraints as a major factor limiting OMT use in their practices. It is worth considering how the results of this study might change if these barriers were mitigated. However, this undertaking would require a systems-based change beyond the scope of this project.

Potential weaknesses of this study include the use of self-reported data and our small study sample. However, the total response rate of 42% was greater than the mean rate of 30% for non-incentivized surveys.²⁵ Also worth mentioning is the increased prevalence of OMM use in the northeastern United States, where osteopathic physicians provide more than a third of general and family medicine patient visits.²⁶ This number is high, considering osteopathic physicians comprise only 8.5% of all licensed physicians in the US.²⁷

Conclusion

Data from this study demonstrated the highest use of, and referral to, OMM during pregnancy in the third trimester and postpartum periods for musculoskeletal complaints such as back pain. These data suggest an explanation for the fact that most publications studying OMM in pregnancy target musculoskeletal complaints, specifically during the third trimester and postpartum periods. Our study also demonstrated that osteopathic physicians were more likely to use or refer to OMM for all indications, compared with allopathic physicians. Our findings therefore suggest that providers with more exposure to, and familiarity with, OMM are more likely to use or refer to OMM during times of lowest use in pregnancy, as evidenced by osteopathic physicians reporting higher frequencies of OMM use during all trimesters and antepartum, as well as higher frequencies of referral for non-musculoskeletal indications, such as constipation, edema, and nasal congestion, This finding has not been represented in prior studies, thereby revealing a significant potential for educational expansion, particularly considering the recent transition to a single accreditation body which allows residency programs to opt for “osteopathic recognition,” effectively exposing more physicians in training to the practice of OMM and its indications for use. Our data thereby suggests that education on the benefits of OMM throughout all stages of pregnancy could prove useful for the future care of obstetric patients, improving outcomes regarding pain and other associated morbidities.