Planning A Study
Resources for turning a question into a study: question frameworks, study designs, sample size and power, protocols, outcome sets and good clinical practice.
Research Questions
| Resource | What it offers | Access |
|---|---|---|
| Research questions, hypotheses and objectives — Canadian Journal of Surgery, 2010 | The PICO format and the FINER criteria for a feasible, relevant question | Free |
| Beyond PICO: the SPIDER tool for qualitative evidence synthesis — Qualitative Health Research, 2012 | A question framework for qualitative and mixed-methods research | Subscription journal |
Study Designs
| Resource | What it offers | Access |
|---|---|---|
| A practical guide for health researchers — World Health Organization | Framing research questions, choosing qualitative or quantitative methods, ethics and presenting findings | Free |
Sample Size & Power
| Resource | What it offers | Access |
|---|---|---|
| Sample size determination and power analysis using the G*Power software — Journal of Educational Evaluation for Health Professions, 2021 | Worked examples of power analysis in G*Power | Free |
| OpenEpi: a web-based epidemiologic and statistical calculator for public health — Public Health Reports, 2009 | Describes OpenEpi, browser calculators that include sample size for proportions, cohort and case-control studies | Free |
| Sealed Envelope power calculators — Sealed Envelope | Superiority, non-inferiority and equivalence trials with binary or continuous outcomes | Free |
| PS: Power and Sample Size Calculation — Vanderbilt University | Sample size and power for dichotomous and continuous outcomes | Free |
| User's guide to sample size estimation in diagnostic accuracy studies — Turkish Journal of Emergency Medicine, 2022 | Sample sizes based on expected sensitivity and specificity | Free |
| PASS — NCSS | Sample size software covering many tests and designs | Paid; free trial |
| nQuery — Statsols | Trial design software, including adaptive designs | Paid; free trial |
Protocols & Outcomes
| Resource | What it offers | Access |
|---|---|---|
| SPIRIT 2025 statement — JAMA, 2025 | The minimum content of a randomised trial protocol | Free |
| Guide to writing a research protocol — Queensland Health | A plain-language protocol guide for any design, written for Australian ethics committees | Free |
| COMET Initiative — COMET Initiative | A database of core outcome sets to consult when choosing trial outcomes | Free |
Good Clinical Practice
| Resource | What it offers | Access |
|---|---|---|
| ICH E8(R1) General considerations for clinical studies — International Council for Harmonisation, published by Japan's Pharmaceuticals and Medical Devices Agency | Building quality into the design of clinical studies | Free |
| Guideline for Good Clinical Practice (GCP) E6(R2) — Saudi Food and Drug Authority | The Saudi good clinical practice requirements for sponsors, investigators and ethics committees | Named document; on the authority's website |
| Trial Forge — Trial Forge | Evidence and tools on trial recruitment, retention and efficiency | Free |