PMID- 35837735 OWN - NLM STAT- MEDLINE DCOM- 20220920 LR - 20221207 IS - 1477-0334 (Electronic) IS - 0962-2802 (Print) IS - 0962-2802 (Linking) VI - 31 IP - 9 DP - 2022 Sep TI - Hunting for protective drugs at the break of a pandemic: Causal inference from hospital data. PG - 1803-1816 LID - 10.1177/09622802221098428 [doi] AB - At the break of a pandemic, the protective efficacy of therapeutic interventions needs rapid evaluation. An experimental approach to the problem will not always be appropriate. An alternative route are observational studies, whether based on regional health service data or hospital records. In this paper, we discuss the use of methods of causal inference for the analysis of such data, with special reference to causal questions that may arise in a pandemic. We apply the methods by using the aid of a directed acyclic graph (DAG) representation of the problem, to encode our causal assumptions and to logically connect the scientific questions. We illustrate the usefulness of DAGs in the context of a controversy over the effects of renin aldosterone system inhibitors (RASIs) in hypertensive individuals at risk of (or affected by) severe acute respiratory syndrome coronavirus 2 disease. We consider questions concerning the existence and the directions of those effects, their underlying mechanisms, and the possible dependence of the effects on context variables. This paper describes the cognitive steps that led to a DAG representation of the problem, based on background knowledge and evidence from past studies, and the use of the DAG to analyze our hospital data and assess the interpretive limits of the results. Our study contributed to subverting early opinions about RASIs, by suggesting that these drugs may indeed protect the older hypertensive Covid-19 patients from the consequences of the disease. Mechanistic interaction methods revealed that the benefit may be greater (in a sense to be made clear) in the older stratum of the population. FAU - Berzuini, Carlo AU - Berzuini C AUID- ORCID: 0000-0001-6056-0489 AD - Centre for Biostatistics, 171083School of Health Sciences, The University of Manchester, Manchester, UK. FAU - Bernardinelli, Luisa AU - Bernardinelli L AD - Department of Brain and Behavioural Sciences, 19001University of Pavia, Pavia, Italy. LA - eng PT - Journal Article DEP - 20220715 PL - England TA - Stat Methods Med Res JT - Statistical methods in medical research JID - 9212457 RN - 0 (Protective Agents) RN - 4964P6T9RB (Aldosterone) RN - EC 3.4.23.15 (Renin) SB - IM MH - Aldosterone MH - Hospitals MH - Humans MH - Hypertension/complications MH - Pandemics MH - Protective Agents MH - Renin MH - *COVID-19 Drug Treatment PMC - PMC9289643 OTO - NOTNLM OT - Covid-19 OT - Observational studies OT - angiotensin receptor blocker OT - angiotensin-converting enzyme inhibitor OT - causal graphical models OT - causal inference OT - conditional independence OT - effect modifier OT - hospital data OT - hypertension OT - matching OT - mechanistic interaction OT - propensity score OT - renin Aldosterone System inhibitors OT - severe acute respiratory syndrome coronavirus 2 EDAT- 2022/07/16 06:00 MHDA- 2022/09/21 06:00 PMCR- 2022/09/01 CRDT- 2022/07/15 03:32 PHST- 2022/07/16 06:00 [pubmed] PHST- 2022/09/21 06:00 [medline] PHST- 2022/07/15 03:32 [entrez] PHST- 2022/09/01 00:00 [pmc-release] AID - 10.1177_09622802221098428 [pii] AID - 10.1177/09622802221098428 [doi] PST - ppublish SO - Stat Methods Med Res. 2022 Sep;31(9):1803-1816. doi: 10.1177/09622802221098428. Epub 2022 Jul 15.