The role of manual therapy for respiratory disorders: an update to Clar et al. Roger Engel, Macquarie University 22 May 2014 Dear Editor We would like to congratulate Christine Clar and her colleagues on the excellent job they have done in undertaking this systematic review (1) and take the opportunity to make a few observations. The review is a timely update of the original Bronfort et al. ‘UK evidence report’ published in 2010 (2). Focusing on the ‘inconclusive’ and ‘negative’ categories reported in Bronfort et al. (2) may be seen by some as a limitation of this review as it excludes new studies showing negative effects if related to a condition that had been reported in the original UK report as clearly ‘positive’. However, an ‘update of evidence’ should be considered in conjunction with the original report of evidence. We therefore believe that this aspect should not be considered a limitation. While a specified time frame and inclusion criteria are required under the PRISMA guidelines (3) the choice of when a review begins and ends and the list of elements that will exclude a trial from the review are decided by the authors of the review and not mandated by any guidelines. This means that these elements are often influenced by pragmatic factors. In the case of this review, the main literature search was carried out in August 2011 and updated in March 2013. Any trial published after March 2013 was therefore not included. Similarly, only primary studies with “at least 20 participants” were included in this review (1). Any trial with less than 20 participants was also excluded. While we understand that limits have to be set to make a systematic review possible they can lead to conclusions that may be ‘out of date’ due to the time elapsed between the end of the search period and publication of the review. Furthermore, if an area of research is relatively new, excluding small studies (n < 20) may overlook some Phase II trials. While we acknowledge that these trials should be interpreted as ‘pilot’ data, we argue they should be included in a review where there is a recognised paucity of studies as these smaller studies may represent the majority of research currently occurring in that field. Clar et al. recognise the effect of a limited number of studies in their recommendation that “more research is needed on non-musculoskeletal conditions” (1). With these points in mind we offer an ‘update’ to their update for the non-musculoskeletal condition of ‘pneumonia/respiratory disorders’ by reporting the publication of two RCTs not included in this systematic review. The first trial was published in October 2013 and titled ‘Short term effects of combining manual therapy and exercise in people with moderate chronic obstructive pulmonary disease: a preliminary clinical trial’ (4). This Phase II trial included 15 participants divided into 3 Groups. One Group received soft tissue therapy only, the second Group received soft tissue therapy and spinal manipulation and the third Group received soft tissue therapy plus spinal manipulation plus a standardised exercise program. Results from this study showed the greatest short term improvements in lung function, exercise capacity and dyspnoea levels in the Group that received all three interventions. The second trial was published in March 2014 and titled ‘Medium term effects of including manual therapy in a pulmonary rehabilitation program for chronic obstructive pulmonary disease (COPD): a randomized controlled pilot trial’ (5). This Phase II trial included 33 participants divided into 3 Groups. One Group received a standardised pulmonary rehabilitation program, the second received the same pulmonary rehabilitation program plus soft tissue therapy and the third Group received the same pulmonary rehabilitation program, the same soft tissue therapy plus spinal manipulation. There was a clinically significant increase in lung function over the medium-term (8 weeks post-intervention) in the Group that received all three interventions compared to the other Groups. Both trials included manipulation carried out by a chiropractor/osteopath, comparison of manual therapy against another therapy (soft tissue therapy or exercise) and outcome measures that assessed function and a characteristic indicator of disease (lung function in these trials). Apart from the first trial not meeting the arbitrarily set required number of participants both studies would have been included in the current systematic review under the classification ‘pneumonia/respiratory disorders’ had they been published prior to March 2013. While we do not wish to detract from the efforts of Clar and her colleagues, our intention is only to make readers aware of newly published work in the event that a further ‘update’ does not occur in the immediate future. By raising the awareness of the existence of these studies we would also like to support Clar et al’s call for more research on non-musculoskeletal conditions. Roger Engel Subramanyam Vemulpad 1. Clar et al. Clinical effectiveness of manual therapy for the management of musculoskeletal and non-musculoskeletal conditions: systematic review and update of UK evidence report. Chiropractic & Manual Therapies 2014, 22:12. 2. Bronfort et al. Effectiveness of manual therapies: the UK evidence report. Chiropractic & Osteopathy 2010, 18:3. 3. PRISMA 2009 checklist. http://www.prisma-statement.org/ 4. Engel RM, Vemulpad S, Beath K. Short term effects of combining manual therapy and exercise in people with moderate chronic obstructive pulmonary disease: a preliminary clinical trial. Journal of Manipulative Physiological Therapeutics 2013, 36:490-496. 5. Engel RM, Gonski P, Beath K, Vemulpad S. Medium term effects of including manual therapy in a pulmonary rehabilitation program for chronic obstructive pulmonary disease (COPD): a randomized controlled pilot trial. Journal of Manual and Manipulative Therapy 2014, doi:10.1179/2042618614Y.0000000074. Competing interests No competing interests.