Somers 1992.
Study characteristics | ||
Methods | Single‐centre prospective randomised controlled trial on 227 participants undergoing breast‐conserving therapy with level I and level II axillary dissection | |
Participants | n = 227. Drain 108, no drain 119. Age of participants, years: drain 60.1 ± 12.8, no drain 59.3 ± 13.8 (mean ± SD) | |
Interventions | Drain versus no drain. Jackson‐Pratt closed suction | |
Outcomes | Seroma, total volume of drainage, total number of aspirations, number of days from surgery to final aspiration, wound infection, lymphoedema, impaired shoulder movement, haematoma, wound dehiscence | |
Notes | Setting: Albert Einstein Medical Centre, Philadelphia, Pennsyvania, USA Funding source not stated |
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Risk of bias | ||
Bias | Authors' judgement | Support for judgement |
Random sequence generation (selection bias) | High risk | Randomisation method based on the last digit of the participant's admission number—pseudorandomisation. Code could easily be broken by surgeon performing several operations |
Allocation concealment (selection bias) | High risk | Method only pseudorandomisation, so easy to crack code |
Blinding of participants and personnel (performance bias) All outcomes | Unclear risk | Cannot blind surgeons or participants to presence/absence of drain. Unclear what effect, if any, this would have |
Blinding of outcome assessment (detection bias) All outcomes | Low risk | Seroma defined: "any palpable or ballottable fluid collection" Aspiration defined: "all collections were aspirated...regardless of size or symptoms" Wound infection defined: "erythema, warmth or purulent drainage at incision site" |
Incomplete outcome data (attrition bias) All outcomes | Unclear risk | Clearly state why four patients were excluded from drain group because drains were left in for > 1 day, in breach of study protocol. 4/109—affects 3% of study population, but unclear why they went > 1 day—all could have developed infection, lots of aspirations required |
Selective reporting (reporting bias) | Low risk | No unreported outcomes |
Other bias | Low risk | No other biases in study design. Good write‐up with lots of detail and good objective definitions of study outcomes |