Spin—the misrepresentation of the study’s actual findings—carries the ability to distort a reader’s perception of a treatments’ full benefits and risks. Recent studies have suggested that spin is common in abstracts of randomized controlled trials and systematic reviews focused on treatments for a variety of medical disorders. Therefore, our primary objective was to evaluate the prevalence of spin in the abstracts of systematic reviews and meta-analyses related to glaucoma treatments. We further assessed whether specific study characteristics were associated with spin, including the methodological quality of a study.
Patients and Methods:
We used a cross-sectional study design searching MEDLINE and Embase databases all for systematic reviews and meta-analyses focused on glaucoma treatments. Each abstract was assessed for the 9 most severe—severity determined by the likelihood of distorting a reader’s perception—types of spin that occur in systematic review abstracts. The screening and data extraction was performed in a duplicate, masked fashion. The methodological quality of each review was assessed using the A MeaSurement Tool to Assess Systematic Reviews (AMSTAR-2) instrument. To evaluate relationships between spin, AMSTAR-2 appraisals, and other study characteristics, we used unadjusted odds ratios and the Fisher exact test.
Only 3 of the 102 abstracts contained spin, with spin type 5 being the most prevalent. No abstracts contained spin types 1, 2, 3, 4, 6, or 8, and no association was found between the presence of spin in an abstract and any particular study characteristic. Using the AMSTAR-2 quality appraisal instrument, 35 (34.3%) of the studies received a methodological quality rating as high, 42 (41.2%) as moderate, 11 (10.8%) as low, and 14 (13.7%) as critically low.
We found that spin is present in only a small proportion of systematic reviews and meta-analyses covering the treatment of glaucoma. In comparison to studies in other fields of medicine, ophthalmology appears to be a leader in publishing systematic reviews and meta-analyses with low rates of spin occurring in the abstract.