Efficacy and safety of osteopathic manipulative treatment: an overview of systematic reviews

Low back pain

Four reviews24–27 with 34 RCTs (41 comparators) and 3369 participants assessed the efficacy of OMT on LBP, including acute LBP, chronic LBP (CLBP), LBP with sciatica, CLBP with menopause symptoms, LBP in obese patients, acute non-specific LBP (ANSLBP), chronic non-specific LBP (CNSLBP) and/or LBP and pelvic girdle pain in pregnancy and postpartum (PP). Taking into account overlapping, there were 22 effective trials with a total of 2053 participants.

The SR performed by De Oliveira and colleagues considered LBP in obese patients, CLBP, CLBP with sciatica and LBP in menopause or pregnancy.24 The review included five trials with 278 participants, and three RCTs were also reported in two more SRs (see online supplemental tables 2, 3 for details). Conflicting results were derived from the primary studies. In the intergroup analysis, OMT was not effective in reducing pain in the majority of the trials. Notably, in all RCTs, the results of functional outcomes were not analysed. Using the PEDro tool, the methodological quality of the five RCTs was classified by the authors as fair to excellent (PEDro range: from 5 to 9 out of 11 points). The OTLE for OMT efficacy in reducing pain in LBP with sciatica and LBP with menopausal symptoms was assessed to be red. Adverse events were not analysed.

The SR of Franke and colleagues included 15 trials with 1502 CNSLBP or ANSLBP participants.25 Ten trials (1141 participants) and 9 RCTs (1046 participants) investigated the effectiveness of OMT on pain and functional status, respectively. Nine RCTs were also reported in other SRs (see online supplemental tables 2, 3 for details). The meta-analysis revealed a medium and small effect in reducing pain and improving functional status, respectively, and a moderate quality of evidence (downgraded due to inconsistency). Moreover, considerable (pain) and moderate (functional status) heterogeneities were found. Similar meta-analysis results (effect and heterogeneity) have also been found in a subanalysis evaluating the effectiveness of OMT in CNSLBP patients (six trials, 771 participants). The GRADE performed by the authors revealed both a moderate quality of evidence for pain and a high quality of evidence for functional status.

Three trials (four comparators) with 242 participants evaluated the effectiveness of OMT versus obstetric care, sham ultrasound and untreated, for NSLBP in pregnant women. A large and a medium effects in reducing pain and improving functional status, respectively, were identified. Considerable (pain) and substantial (functional status) heterogeneity were found. GRADE evaluation by the authors reported a low quality of evidence for both outcomes.

Two RCTs with 119 participants evaluated the effectiveness of OMT for NSLBP in PP women. A large effect of OMT in reducing pain and improving functional status was identified. No heterogeneity was found. However, a moderate quality of evidence for both outcomes was revealed. The methodological quality of all RCTs, evaluated by the authors using the RoB from the CBRG,18 reported a low and a high RoB for 13 and 2 RCTs, respectively. However, considering the last version of the CBN Group,19 we rated all RCTs at high RoB [domains at high RoB (% of RCTs): care provider (100%), patient blinding (67%), outcome assessor blinding (67%), groups similar at baseline (27%), lack of intention to treat analysis use (27%), free of selective outcome report (13%), dropouts described+acceptable (7%), similar timing outcome assessment (7%) and compliance acceptable (7%)]. The OTLE for the outcomes of each condition was assessed to be yellow.

Adverse events were evaluated in only 4 out of the 15 primary studies. Two RCTs reported minor adverse events such as stiffness and tiredness, one no adverse event and the last one evidenced adverse events not related to the treatment intervention.

In another SR, Franke and colleagues26 identified eight RCTs with 850 participants evaluating the efficacy of OMT on NSLBP and pelvic girdle pain in pregnancy (five RCTs, seven comparisons) and on NSLBP in PP women (three trials and three comparisons) (see online supplemental tables 2, 3 for overlapping). The pooled analysis of five RCTs with 677 pregnancy participants reported the efficacy of OMT in reducing pain and improving functional status; however, a medium effect and a considerable heterogeneity were revealed. The GRADE performed by the authors indicated a moderate quality of evidence.

The meta-analysis including three studies with 173 PP participants revealed a significant effect in favour of OMT in reducing pain and improving functional status, although a large effect and substantial/considerable heterogeneity for both outcomes were reported. The GRADE performed by the authors also found a low quality of evidence.

The methodological quality of the included studies evaluated by the authors using the CBRG,18 identified a low RoB for all RCTs. Considering the CBN Group,19 we rated all RCTs as at high RoB [domains at high RoB (% of RCTs): patient binding (100%), care provider binding (100%), outcome assessor blinding (100%), dropouts described +acceptable (25%), group similar at the baseline (25%), intention to treat analysis (25%), similar timing outcome assessment (25%) and compliance acceptable (12%)]. The OTLE for the outcomes of each condition was assessed to be yellow.

Concerning the adverse events, one study reported occasional tiredness in some patients after OMT, two studies (personal communications to authors SR) did not find adverse events and the remaining five studies did not analyse adverse events.

The SR by Dal Farra and colleagues27 evaluated the effectiveness of osteopathic interventions, performed by any type of manual therapist in CNSLBP patients. A subgroup analysis evaluating the effectiveness of OMT performed only by osteopaths identified six trials (eight comparisons) with 739 participants; five trials were also reported in other two further SRs (see online supplemental tables 2, 3 for more details).

The authors revealed a significant effect, clinically relevant according to the CBN Group,19 of OMT in reducing pain (medium effect) and improving functional status (small effect). However, substantial heterogeneity and a low quality of evidence (GRADE) were reported for both outcomes.

A further subanalysis, including two trials (three comparisons) with 548 participants, did not find evidence of OMT efficacy on functional status after a long-term treatment (12 weeks follow-up). Low quality of evidence and no heterogeneity were reported. The methodological quality of the primary studies, evaluated by the authors using the CBN Group,19 reported a high RoB for all RCTs [domains at high RoB (% of RCTs): high RoB for care provider (100%), patient blinding (50%), outcome assessor blinding (17%), participant allocation (33%) and reporting bias (17%)]. The OTLE for the outcomes was assessed to be yellow.

With regards to adverse events, a trial reported an increase in back muscle spasticity in one patient treated with OMT.

Chronic non-cancer pain

The SR by Rehman and colleagues29 evaluated the efficacy of osteopathic interventions performed by manual therapists in chronic non-cancer pain. Sixteen RCTs were identified; however, we considered pooled analyses in which the trials were only performed by osteopaths (see online supplemental tables 2, 3 for overlapping). A pooled analysis, including 6 RCTs with 728 participants (six comparators), found the efficacy of OMT versus standard care in reducing pain severity (small ES, moderate quality of evidence and low level of heterogeneity). Moreover, another pooled analysis including two trials with 486 participants revealed the efficacy of OMT versus standard care in improving disability (large ES, moderate quality of evidence and no heterogeneity). Similarly, the pooled analysis of the other two trials with 210 participants found that OMT versus standard care improved the quality of life (medium effect, moderate quality of evidence and no heterogeneity).

The methodological quality of the included studies was performed by the authors using a modified version of the Handbook of Cochrane33 where only six domains were considered (random sequence generation, allocation concealment, blinding of participants, healthcare provider, outcome assessors and dropout rates). According to this modified version, the quality of the RCTs was reported by the authors to be at high RoB [domains at high RoB (% of RCTs): for patient blinding (100%), care provider blinding (100%), outcome assessor blinding (57%), random sequence generation (29%), participant allocation concealment (29%), and dropout >20% (43%)]. The OTLE for the outcomes of each condition was assessed to be yellow.

Adverse events were not considered by the SR authors.