Cross-sectional vs Cohort Studies
How the two most common observational designs differ, what each can tell you, and how to choose between them.
Research Methodology
How to Structure a Medical Research Protocol
The essential sections of a protocol or synopsis, and what reviewers look for in each.
Research Methodology
A protocol is the blueprint of your study. A clear protocol makes ethics review smoother and gives you a reference throughout data collection.
Title and background
The title should state the design, population and main variables. The background should briefly explain what is known, what is not, and why your study is needed.
Research question and objectives
State one primary objective and a small number of secondary objectives. Each objective should be measurable and linked to a specific analysis.
Methods
- Study design, setting and duration
- Study population, inclusion and exclusion criteria
- Sample size with justification, and sampling technique
- Variables and operational definitions
- Data collection procedures and tools (proforma / CRF)
- Statistical analysis plan
Ethical considerations
Describe informed consent, confidentiality, risk to participants and how data will be stored. Refer to applicable national guidelines, such as the ICMR National Ethical Guidelines.
References and annexures
Use a consistent reference style (commonly Vancouver). Attach the consent form, participant information sheet and data collection proforma.
SPIRIT as a checklist
For trials, the SPIRIT 2013 statement lists recommended protocol items. Many of its items are useful checks for observational protocols too.
This article is for general educational purposes. Always follow your institution’s guidelines and your guide’s advice.