10.6084/m9.figshare.6213854.v1
Catherine E. Oldenburg
Catherine
E. Oldenburg
N. Venkatesh Prajna
N. Venkatesh
Prajna
Tiruvengada Krishnan
Tiruvengada
Krishnan
Revathi Rajaraman
Revathi
Rajaraman
Muthiah Srinivasan
Muthiah
Srinivasan
Kathryn J. Ray
Kathryn
J. Ray
Kieran S. O’Brien
Kieran S.
O’Brien
M. Maria Glymour
M.
Maria Glymour
Travis C. Porco
Travis
C. Porco
Nisha R. Acharya
Nisha R.
Acharya
Jennifer Rose-Nussbaumer
Jennifer
Rose-Nussbaumer
Thomas M. Lietman
Thomas
M. Lietman
Regression Discontinuity and Randomized Controlled Trial Estimates: An Application to The Mycotic Ulcer Treatment Trials
Taylor & Francis Group
2018
Causal inference
fungal keratitis
randomized controlled trial
regression discontinuity
2018-05-02 20:15:54
Journal contribution
https://tandf.figshare.com/articles/journal_contribution/Regression_Discontinuity_and_Randomized_Controlled_Trial_Estimates_An_Application_to_The_Mycotic_Ulcer_Treatment_Trials/6213854
<p><b><i>Purpose</i></b>: We compare results from regression discontinuity (RD) analysis to primary results of a randomized controlled trial (RCT) utilizing data from two contemporaneous RCTs for treatment of fungal corneal ulcers.</p> <p><b><i>Methods</i></b>: Patients were enrolled in the Mycotic Ulcer Treatment Trials I and II (MUTT I & MUTT II) based on baseline visual acuity: patients with acuity ≤ 20/400 (logMAR 1.3) enrolled in MUTT I, and >20/400 in MUTT II. MUTT I investigated the effect of topical natamycin versus voriconazole on best spectacle-corrected visual acuity. MUTT II investigated the effect of topical voriconazole plus placebo versus topical voriconazole plus oral voriconazole. We compared the RD estimate (natamycin arm of MUTT I [<i>N</i> = 162] versus placebo arm of MUTT II [<i>N</i> = 54]) to the RCT estimate from MUTT I (topical natamycin [<i>N</i> = 162] versus topical voriconazole [<i>N</i> = 161]).</p> <p><b><i>Results</i></b>: In the RD, patients receiving natamycin had mean improvement of 4-lines of visual acuity at 3 months (logMAR −0.39, 95% CI: −0.61, −0.17) compared to topical voriconazole plus placebo, and 2-lines in the RCT (logMAR −0.18, 95% CI: −0.30, −0.05) compared to topical voriconazole.</p> <p><b><i>Conclusions</i></b>: The RD and RCT estimates were similar, although the RD design overestimated effects compared to the RCT.</p>