Effect of colonoscopy screening on risks of colorectal cancer and related death

October 2022
New England Journal of Medicine

Michael Bretthauer, Magnus Løberg, Paulina Wieszczy, Mette Kalager, Louise Emilsson, Kjetil Garborg, Maciej Rupinski, Evelien Dekker, Manon Spaander, Marek Bugajski, Øyvind Holme, Ann G. Zauber, Nastazja D. Pilonis, Andrzej Mroz, Ernst J. Kuipers, Joy Shi, Miguel A. Hernán, Hans-Olov Adami, Jaroslaw Regula, Geir Hoff, and Michal F. Kaminski, for the NordICC Study Group

We present the results from the NordICC trial, a pragmatic, randomized trial involving men and women aged 55 to 64 years of age from Poland, Norway, Sweden, and the Netherlands between 2009 and 2014 who were randomized to receive an invitation to undergo a single screening colonoscopy or to receive no invitation or screening.

Mendelian randomization with repeated measures of a time-varying exposure: an application of structural mean models

January 2022
Epidemiology

Joy Shi, Sonja A. Swanson, Peter Kraft, Bernard Rosner, Immaculata De Vivo, and Miguel A. Hernán

We describe instrumental variable analysis with a time-varying exposure, with an emphasis on the types of causal estimands that can be targeted, the assumptions required for identification, and the use of g-estimation of structural mean models to estimate these effects.

Instrumental variable estimation for a time-varying treatment and a time-to-event outcome via structural nested cumulative failure time models

November 2021
BMC Medical Research Methodology

Joy Shi, Sonja A. Swanson, Peter Kraft, Bernard Rosner, Immaculata De Vivo, and Miguel A. Hernán

We propose the use of g-estimation of structural nested cumulative failure time models for instrumental variable analyses of time-varying exposures and failure time outcomes.

The effect of maternal multiple micronutrient supplementation on female early infant mortality is fully mediated by increased gestation duration and intrauterine growth

February 2020
The Journal of Nutrition

Mary K. Quinn, Emily R. Smith, Paige L. Williams, Willy Urassa, Joy Shi, Gernard Msamanga, Wafaie W. Fawzi, Christopher R. Sudfeld

We assess the extent to which the effect of maternal micronutrient supplementation (MMS) in pregnancy on infant mortality is mediated by birth weight, gestation age and weight-for-gestational age.