Quasi-experimental study designs series—paper 5: a checklist for classifying studies evaluating the effects on health interventions—a taxonomy without labels

Abstract

ObjectivesThe aim of the study was to extend a previously published checklist of study design features to include study designs often used by health systems researchers and economists. Our intention is to help review authors in any field to set eligibility criteria for studies to include in a systematic review that relate directly to the intrinsic strength of the studies in inferring causality. We also seek to clarify key equivalences and differences in terminology used by different research communities.Study Design and SettingExpert consensus meeting.ResultsThe checklist comprises seven questions, each with a list of response items, addressing: clustering of an intervention as an aspect of allocation or due to the intrinsic nature of the delivery of the intervention; for whom, and when, outcome data are available; how the intervention effect was estimated; the principle underlying control for confounding; how groups were formed; the features of a study carried out after it was designed; and the variables measured before intervention.ConclusionThe checklist clarifies the basis of credible quasi-experimental studies, reconciling different terminology used in different fields of investigation and facilitating communications across research communities. By applying the checklist, review authors' attention is also directed to the assumptions underpinning the methods for inferring causality.

Scaling-up primary health care-based prevention and management of heavy drinking at the municipal level in middle-income countries in Latin America: Background and protocol for a three-country quasi-experimental study

“…While full control via randomization, and thus establishment of causality is not possible, together with the qualitative evaluation component of the study, we will be able to clearly identify the mechanisms which were crucial in leading to the outcomes. According to a recent 7-item checklist for classifying quasi-experimental studies for Cochrane reviews 162 , our approach is, nevertheless, ranked as a strong design.…”

Comparative effectiveness of concurrent chemoradiotherapy versus EGFR‐tyrosine kinase inhibitors for the treatment of clinical stage IIIb lung adenocarcinoma patients with mutant EGFR

“…Unresected AJCC 7E clinical stage IIIb lung adenocarcinoma patients diagnosed between 2011/6 and 2015 with m EGFR and good Eastern Cooperative Oncology Group performance status (ECOG PS) 0–1, aged ≥ 18 were included in the study . Patients who underwent surgery as part of their treatment before disease progression, received palliative treatment, or had other cancer(s) within three years were excluded.…”

Single‐track year‐round education for improving academic achievement in U.S. K‐12 schools: Results of a meta‐analysis

“…This near-constant use of the school creates a second set of problems. The school must operate 1 This issue is further complicated by divergent terminology, including historically controlled study (Higgins et al, 2013), historically controlled cohort study (Reeves, Wells, & Waddington, 2017), and single group study design with historical comparison (Paulus et al, 2014). 2 Aside from cross-national and cross-cultural differences, the typical number of instructional days varies by country.…”