When Trends Matter: Rethinking Before-After Analyses

When Trends Matter: Rethinking Before-After Analyses

🎙 Sabina (Women's Health Research Institute) 👥 251 📅 June 15, 2026 ⏱ 56 min 👁 12 📄 tutorial 🧭 2026-08-16
Available in: English (current) Français

Keywords

interrupted time seriesARIMAbefore-after analysisCOVID-19health care access

Summary

This video is a lecture from the Women’s Health Research Institute, presented by Sabina, focusing on the use of interrupted time series (ITS) and ARIMA models for evaluating the impact of events like the COVID-19 pandemic on health outcomes. The speaker uses two published papers as real-world examples: one on recurrent pregnancy loss management and another on conception rates. She explains the rationale for choosing ITS over simple before-after comparisons, emphasizing the need to account for underlying trends and to estimate counterfactuals. The lecture covers the statistical foundations, including linear regression, Newey-West standard errors, and the importance of checking assumptions like stationarity. For ARIMA, she discusses model selection, autocorrelation, and the use of historical data for forecasting. The presentation includes practical details on data preparation, such as calculating conception dates and incorporating socioeconomic deprivation indexes. The speaker also highlights limitations, such as having only four post-pandemic points in one study, which precluded ITS analysis. Overall, the video provides a comprehensive tutorial on these methods, aimed at researchers in health sciences.

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Critical Evaluation

Value of the Information & Strength of the Argument

The video provides valuable insights into the application of interrupted time series and ARIMA models in health research, using concrete examples from published studies. The speaker clearly explains the conceptual differences between these methods and their appropriate use cases, emphasizing the importance of accounting for trends and seasonality. The argumentation is solid, as she walks through the statistical reasoning and practical steps, including checking assumptions and interpreting results. However, the presentation is somewhat informal and lacks rigorous citation of sources for the methods described, which may reduce its standalone credibility. The speaker also acknowledges limitations, such as the need for sufficient data points and the potential for confounding, which strengthens the overall argumentation.

Scientific Rigor, Source Quality, Title Accuracy

The video demonstrates scientific rigor in its methodological explanations, referencing two peer-reviewed papers and standard statistical techniques. However, the sources cited are not explicitly listed in the description, and the speaker mentions using macros found online without providing specific references. The title accurately reflects the content, focusing on the importance of trends in before-after analyses. The presentation is consistent with the title, as it delves into methods that address trend-related issues. The lack of formal citations and the informal style slightly detract from the overall rigor, but the content is based on established statistical practices.

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Title / Content Match

The title accurately reflects the content, which focuses on the importance of considering trends in before-after analyses, specifically through interrupted time series and ARIMA methods.

Quality & Reliability

7/10

The video is a technical tutorial by a researcher from a recognized institute, presenting real published studies and explaining statistical methods (interrupted time series, ARIMA) with practical examples. The methods are standard and well-established, but the presentation is informal and lacks detailed citations or verification of the described macros. The speaker acknowledges limitations and provides context, but the content is not peer-reviewed in this format.

Key Moments

Cited Sources

  • Impact of COVID-19 pandemic on pregnancy complications at conception resulting in birth — Mentioned as a published paper related to the methods discussed.
  • COVID-19 and recurrent pregnancy loss management trends and clinical care from a tertiary center — Mentioned as a published paper used as an example.

Concurring Sources

Contribution & Novelties

The video provides a practical, example-driven explanation of interrupted time series and ARIMA models, specifically tailored to health services research. It bridges the gap between theoretical knowledge and application by using real published studies, including details on data preparation, model selection, and interpretation. The inclusion of socioeconomic deprivation indexes adds a novel dimension to the analysis. The speaker also clarifies common pitfalls, such as the need for sufficient data points and the importance of stationarity.

Pour aller plus loin :

125 words

Radar Profile

The radar profile shows high scores in quantity of information, technical level, and reliability, indicating a content-rich and methodologically sound presentation. The quality of information is also high, but the slightly lower score suggests some informality and lack of formal citations. Overall, the video is a strong educational resource for researchers.

Reliability 7/10