ArticleClinical epidemiology2019
Sample size and power considerations for ordinary least squares interrupted time series analysis: a simulation study.
Article in Clinical epidemiology, 2019. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 50 papers.
What it found
Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.
The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.
Who cites it
50 citing papers in PubMed.
- Disparities in Autism Spectrum Disorder and Perinatal Risk Factors.JAMA network open · 2026Article
- Did government subsidy program improve quality of care for children with complex chronic conditions in children's hospitals? A quasi-experimental study in South Korea.Clinical and experimental pediatrics · 2026Article
- A Comprehensive Simulation Study to Evaluate the Effect Size and Study Length Relationship in Single-Group Interrupted Time Series Analysis.Evaluation & the health professions · 2026Article
- Changes in pediatric service utilization for depression and anxiety during the COVID-19 pandemic.BMC health services research · 2026Article
- Assessing the effectiveness of decentralised antenatal ultrasound in a primary health care clinic compared with a hospital-based service in rural South Africa: an interrupted time series analysis.BMC pregnancy and childbirth · 2025Article
- Perioperative Medicine for Older People Undergoing Surgery Scale Up (POPS-SUp): study protocol.BJS open · 2025Article
- Rapid Diagnostic Stewardship and Blood Culture Use in a Pediatric Medical Center.JAMA network open · 2025Article
- Outcome Evaluation of a Multimodal Suicide Prevention Program Designed Through International Collaboration: Protocol for a Controlled Interrupted Time Series Study.JMIR research protocols · 2025Article
- The Incidence and Characteristics of U.K. Stranger Sex Offenses Fluctuated With Public Health Measures During the COVID-19 Pandemic.Psychology of violence · 2025Article
- Effects of marine heat waves and cold spells on a polar shallow water ecosystem.Scientific reports · 2025Article
- Effectiveness of a formulary system on prophylactic oral proton pump inhibitors for drug-induced peptic ulcer in a Japanese tertiary hospital: an interrupted time series analysis.Journal of pharmaceutical health care and sciences · 2025Article
- A multifaceted intervention to improve diagnosis and early management of hospitalised patients with suspected acute brain infections in Brazil, India, and Malawi: an international multicentre intervention study.Lancet (London, England) · 2025Observational
- The impact of Covid-19 on harm reduction policies in Iran: an interrupted time series analysis.Harm reduction journal · 2025Article
- Common Seasonal Pathogens and Epidemiology of Henoch-Schönlein Purpura Among Children.JAMA network open · 2024Article
- Design and statistical analysis reporting among interrupted time series studies in drug utilization research: a cross-sectional survey.BMC medical research methodology · 2024Article
- Article
- Article
- Impact of community mental health services on the adult psychiatric admission through the emergency unit: a 20-year population-based study.The Lancet regional health. Western Pacific · 2023Article
- Article
- Impact of national recommendations for routine pertussis vaccination during pregnancy on infant pertussis in Ontario, Canada: a population-based time-series study.BMC pregnancy and childbirth · 2023Article
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
5 authors.
Funding
Abstract
Interrupted time series (ITS) analysis is being increasingly used in epidemiology. Despite its growing popularity, there is a scarcity of guidance on power and sample size considerations within the ITS framework. Our aim of this study was to assess the statistical power to detect an intervention effect under various real-life ITS scenarios. ITS datasets were created using Monte Carlo simulations to generate cumulative incidence (outcome) values over time. We generated 1,000 datasets per scenario, varying the number of time points, average sample size per time point, average relative reduction post intervention, location of intervention in the time series, and reduction mediated via a 1) slope change and 2) step change. Performance measures included power and percentage bias. We found that sample size per time point had a large impact on power. Even in scenarios with 12 pre-intervention and 12 post-intervention time points with moderate intervention effect sizes, most analyses were underpowered if the sample size per time point was low. We conclude that various factors need to be collectively considered to ensure adequate power for an ITS study. We demonstrate a means of providing insight into underlying sample size requirements in ordinary least squares (OLS) ITS analysis of cumulative incidence measures, based on prespecified parameters and have developed Stata code to estimate this.
Indexed as
Identifiers
What OpenQuestion holds
Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.