General health measures in shoulder surgery: are we powered for success?

BACKGROUND: Surgeons, policymakers, and payers increasingly use changes in general health to guide decision-making. It is unknown how such measures are incorporated into shoulder surgery research, how strongly they are associated with changes in shoulder-specific outcomes, and whether they are appropriately powered. METHODS: PubMed was searched for articles reporting shoulder-specific and general health measures after rotator cuff repair and total shoulder arthroplasty. Study characteristics, results at the study group level, reporting of power calculations, and statistical significance were recorded. Meta-regression was employed to describe the association of changes between shoulder-specific and general health measures. RESULTS: Of 360 identified abstracts, 21 articles with 28 patient groups were included. Only 1 article was published before 2000. There was a strong association of changes between shoulder-specific and general health measures (r = 0.66; P < .001). Power calculations were mentioned in 33% of studies and based on shoulder-specific measures. Of 20 studies conducting hypothesis tests, 75% reported agreement regarding the statistical significance of shoulder-specific and general health tests. Of 5 discordant studies, 4 found the shoulder-specific measure statistically significant and not the general health measure. CONCLUSION: Shoulder surgery research increasingly reports changes in general health measures that are associated with changes in shoulder-specific measures, suggesting that improvements in shoulder symptoms increase quality of life. When disagreement exists, it usually results from the general health measure's not meeting statistical significance, which may simply reflect type II error. Research reporting general health measures should carefully report power considerations to avoid misinterpretation of findings failing to reach statistical significance.

The Effect of Image-Guided Corticosteroid Injections on Thumb Carpometacarpal Arthritis.

Background: Arthritis involving the thumb carpometacarpal (CMC) joint is common in the adult population. Initial treatment includes corticosteroid injections. Injections can be performed with image guidance to assist with placement; however, the clinical benefits are unclear. Methods: This retrospective study used Truven Health Marketscan Research Databases to identify patients from 2003 to 2014 with common International Classification of Diseases, Ninth Revision (ICD-9) codes for osteoarthritis of the CMC joint, Common Procedural Terminology (CPT) codes for image and non-image-guided injections, and codes for surgical interventions. Length of time from injection until subsequent injection(s) and/or surgery was extrapolated for identified patients. Analysis of variance and binomial logistic regression were used to compare continuous variables and calculate odds ratios, respectively. Results: We identified 62 333 patients (68% women, 32% men), average age 59.7, with common ICD-9 diagnostic codes for CMC arthritis with respective injection CPT codes. The average number of days between the first and second injection for patients treated with non-guided injection was 237.3 versus 266.7 for image-guided injections. Of the 62333 patients, 8107 went on to operative treatment. Among operative patients, the average number of days to surgery following non-guided injection was 317.7 versus 333.7 days in the image-guided group. The average cost of performing non-image-guided injections was $203 less than using ultrasound. Conclusions: Image-guided thumb CMC injections do not result in significant increases in time between injections and do not lead to a meaningful delay to surgery. Future research needs to clarify the value of image-guided CMC injections in an increasingly economically conscientious health care environment.