Miso Krsticevic1, Dragica Saric2, Frano Saric3, Ema Slapnicar4, Krste Boric1, Svjetlana Dosenovic5, Antonia Jelicic Kadic6, Milka Jeric Kegalj7, Livia Puljak8. 1. Department of Orthopaedics, University Hospital Split, Spinciceva 1, Split 21000, Croatia. 2. Health Center Dr. Ante Franulovic Vela Luka, Kale 1, Vela Luka 20270, Croatia. 3. Department of Radiology, University Hospital Split, Spinciceva 1, Split 21000, Croatia. 4. Medical Studies, University of Split School of Medicine, Soltanska 2, Split 21000, Croatia. 5. Department of Anesthesiology & Intensive Care Medicine, University Hospital Split, Spinciceva 1, Split 21000, Croatia. 6. Department of Pediatrics, University Hospital Split, Spinciceva 1, Split 21000, Croatia. 7. Department of Dermatovenerology, General Hospital Zadar, Boze Pericica 5, Zadar 23000, Croatia. 8. Department of Evidence-Based Medicine and Health Care, Catholic University of Croatia, Ilica 242, 10000 Zagreb, Croatia.
Abstract
Aim: Outcome reporting bias (ORB) occurs when outcomes planned in a study protocol are subsequently not reported or are partially reported. Our aim was to analyze ORB in randomized controlled trials (RCTs) about conservative interventions for osteoarthritis (OA) by comparing registered protocols and published manuscripts, as well as association between study funding type and intervention type, and ORB in those RCTs. Materials & methods: We analyzed RCTs that were published in a peer-review journal and analyzed any type of conservative intervention for treatment of OA in humans that reported in the manuscript registration in a public clinical trial registry and provided unique registration identifier. We extracted data indicating ORB by comparing outcomes in protocol and published article, and characteristics of trials. Results: In 190 (57%) of 334 included RCTs, it was indicated in the manuscript that a trial was registered. In 48% of trials we found discrepancies in number, type or time point of primary efficacy outcome between protocol and manuscript. Significantly less discrepancies in primary efficacy outcomes between protocols and published articles were found in trials funded by a commercial sponsor (p = 0.0062) and trials of pharmacological interventions (p = 0.0016). Conclusion: Trials about conservative therapies for OA have high prevalence of discrepancies between protocol and publication, and frequent ORB. This may mislead readers of published results because it has been shown that ORB can lead to both overestimation and underestimation of effects of interventions, depending on the intervention and outcome. Efforts to prevent nonregistration of protocols and selective reporting are needed.
Aim: Outcome reporting bias (ORB) occurs when outcomes planned in a study protocol are subsequently not reported or are partially reported. Our aim was to analyze ORB in randomized controlled trials (RCTs) about conservative interventions for osteoarthritis (OA) by comparing registered protocols and published manuscripts, as well as association between study funding type and intervention type, and ORB in those RCTs. Materials & methods: We analyzed RCTs that were published in a peer-review journal and analyzed any type of conservative intervention for treatment of OA in humans that reported in the manuscript registration in a public clinical trial registry and provided unique registration identifier. We extracted data indicating ORB by comparing outcomes in protocol and published article, and characteristics of trials. Results: In 190 (57%) of 334 included RCTs, it was indicated in the manuscript that a trial was registered. In 48% of trials we found discrepancies in number, type or time point of primary efficacy outcome between protocol and manuscript. Significantly less discrepancies in primary efficacy outcomes between protocols and published articles were found in trials funded by a commercial sponsor (p = 0.0062) and trials of pharmacological interventions (p = 0.0016). Conclusion: Trials about conservative therapies for OA have high prevalence of discrepancies between protocol and publication, and frequent ORB. This may mislead readers of published results because it has been shown that ORB can lead to both overestimation and underestimation of effects of interventions, depending on the intervention and outcome. Efforts to prevent nonregistration of protocols and selective reporting are needed.