Predictive factors for reporting adverse events following spinal manipulation in randomized clinical trials - secondary analysis of a systematic review

Short-Term Effect of Spinal Manipulation on the Magnitude of Exophoria in Adults Who Are Asymptomatic: A Randomized Controlled Trial

OBJECTIVE

This study aimed to assess the immediate and short-term effects of cervical spinal manipulation (SM), compared with a placebo, on the magnitude of near and distance exophoria in adults with asymptomatic exophoria.

METHODS

In this single-blind, randomized controlled trial, individuals with a clinical diagnosis of horizontal exophoria confirmed with the prism alternating cover test (PACT) were allocated to a single intervention session using a high-velocity, low-amplitude cervical SM technique or a sham intervention (manual contact under the head). Outcomes were the magnitude of horizontal heterophoria, as a measure of binocular vision efficiency at near (40 cm) or distance (4 m) fixation, using the PACT. Evaluations were made at baseline, immediately after intervention, and at a 1-week follow-up.

RESULTS

From May to September 2021, 44 volunteers (23 women), with a mean age of 35 (SD = 9.5) years, were recruited and equally distributed into the study groups. All participants completed follow-up assessments, and no adverse events were reported. There was a significant time × group interaction for exophoria at near vision, but not at distance fixation. The SM group showed a significant decrease of near exophoria compared with the control group at the 1-week follow-up (mean difference = -1.09 prism diopters; 95% CI = -0.20 to -1.98 prism diopters).

CONCLUSION

The use of cervical SM therapy resulted in a significant reduction of the magnitude of horizontal exophoria at near vision (medium effect size), compared with the placebo, in young adults who are asymptomatic. However, these effects were not observed at distance fixation and should be considered cautiously due to the pre-post design with a single intervention session and the short-term follow-up.

IMPACT

The findings suggest short-term benefits of SM therapy can manage undiagnosed ocular convergence disorders, although changes were not clinically relevant.

Reporting of adverse events associated with spinal manipulation in randomised clinical trials: an updated systematic review

OBJECTIVES

To describe if there has been a change in the reporting of adverse events associated with spinal manipulation in randomised clinical trials (RCTs) since 2016.

DESIGN

A systematic literature review.

DATA SOURCES

Databases were searched from March 2016 to May 2022: MEDLINE (Ovid), Embase, CINAHL, ICL, PEDro and Cochrane Library. The following search terms and their derivatives were adapted for each platform: spinal manipulation; chiropractic; osteopathy; physiotherapy; naprapathy; medical manipulation and clinical trial.

METHODS

Domains of interest (pertaining to adverse events) included: completeness and location of reporting; nomenclature and description; spinal location and practitioner delivering manipulation; methodological quality of the studies and details of the publishing journal. Frequencies and proportions of studies reporting on each of these domains were calculated. Univariable and multivariable logistic regression models were fitted to examine the effect of potential predictors on the likelihood of studies reporting on adverse events.

RESULTS

There were 5399 records identified by the electronic searches, of which 154 (2.9%) were included in the analysis. Of these, 94 (61.0%) reported on adverse events with only 23.4% providing an explicit description of what constituted an adverse event. Reporting of adverse events in the abstract has increased (n=29, 30.9%) while reporting in the results section has decreased (n=83, 88.3%) over the past 6 years. Spinal manipulation was delivered to 7518 participants in the included studies. No serious adverse events were reported in any of these studies.

CONCLUSIONS

While the current level of reporting of adverse events associated with spinal manipulation in RCTs has increased since our 2016 publication on the same topic, the level remains low and inconsistent with established standards. As such, it is imperative for authors, journal editors and administrators of clinical trial registries to ensure there is more balanced reporting of both benefits and harms in RCTs involving spinal manipulation.

Evolution of bias and sample size in postoperative pain management trials after hip and knee arthroplasty

BACKGROUND

Bias (systematic error) and small trial sample size (random error) may induce imprecise and exaggerated treatment effects in randomised controlled trials (RCTs). To avoid this, SPIRIT- and CONSORT-guidelines, and Cochrane Collaboration bias recommendations were developed. We investigated risk of bias and trial sample size development over time in postoperative pain trials.

METHODS

This study was based on data from two systematic reviews regarding pain management after total hip arthroplasty (THA) or total knee arthroplasty (TKA). RCTs of analgesic interventions with a comparator control group were included. Primary outcomes were risk of bias and trial sample size developments over time. We calculated cumulated bias scores ranging from 0 to 14 based on Cochrane's seven bias domains (0 = low; 1 = unclear, 2 = high). Developments were evaluated with run and control charts. Further, we compared data from trials published between 1990-1999 and 2010-2016.

RESULTS

We included 171 trials published between 1989 and 2016. Overall, the summarised risk of bias decreased, mainly due to better randomization and allocation concealment. Visual inspection suggested an on-going improvement that started around 2007. Trial sample size did not change significantly. For trials published between 1990-1999 and 2010-2016 adequate reporting increased from 36% to 75% for random sequence generation, from 9% to 38% for allocation concealment and from 27% to 52% for blinding of participants/personnel.

CONCLUSION

Risk of bias for RCTs regarding postoperative pain management after THA and TKA has decreased from 2007 to 2016, mainly due to better randomization and allocation concealment. Deficiencies remain. Thus, reporting according to validated guidelines is essential. Sample sizes did not change significantly.