The Methods section is the part of a medical article that receives the most reviewer criticism. "Methods is poorly described", "Statistical methods are not clearly explained", "Sample size justification is missing", these phrases are frequently encountered in major revision or rejection letters.
A well-written Methods section both ensures the reproducibility of your study and creates a perception of methodological reliability among reviewers.
Mandatory Subsections of the Methods Section
Although every journal has its own format, the universally expected subsections are as follows:
Study Design and Ethical Approval
Participants / Patients
Data Collection
Outcome Measures
Statistical Analysis
How to Write the Study Design
The first sentence should clearly define the study design.
Weak: "In this study, 200 patients were examined."
Strong: "This retrospective cohort study was conducted on consecutive patients who underwent total knee arthroplasty at the [Institution name] Orthopedics and Traumatology Clinic between January 2020 and December 2022. The study was approved by the [Ethics Committee name] (Protocol No: XX/XX) and conducted in accordance with the Declaration of Helsinki."
Participants Subsection
Inclusion and exclusion criteria should be clear and specific.
Inclusion criteria:
- Age range
- Diagnostic criteria (which classification system?)
- Type of surgery or treatment
- Follow-up period
Exclusion criteria:
- Those with missing data
- Comorbid conditions
- Those who had previously received treatment
A sample size justification must always be written:
"The power analysis showed that, based on [reference], assuming [effect size], alpha=0.05, and power=0.80, a minimum of [N] patients was required in each group."
Data Collection Subsection
Who collected it, with which tools, and how was it standardized?
"All data were collected retrospectively by reviewing patient files, using a standard form, by two independent researchers (B.S. and X.Y.). Disagreements were resolved by the opinion of a third researcher (Z.W.)."
For image measurements: Which software, which technique, and what is the inter-rater reliability (ICC)?
Statistical Analysis Subsection
This is the part that most researchers leave the most superficial.
The structure should be as follows:
- How were descriptive statistics presented?
"Continuous variables were expressed as mean and standard deviation for normally distributed data, and as median and interquartile range for non-normally distributed data. Categorical variables were presented as frequency and percentage."
- Was a normality test performed?
"The conformity of the data to a normal distribution was assessed with the Shapiro-Wilk test."
- Which comparison tests were used and why?
"For comparisons between two independent groups, Student's t-test (for normally distributed data) or the Mann-Whitney U test (for non-normally distributed data) was used. Categorical variables were compared with the chi-square or Fisher's exact test."
- Was multivariate analysis performed?
"Multivariate logistic regression analysis was applied to identify independent predictors. Variables with p<0.20 in univariate analysis were included in the model."
- Which software was used?
"Statistical analyses were performed using SPSS 26.0 (IBM Corp., Armonk, NY). P<0.05 was considered statistically significant."
The Most Common Reviewer Criticisms and Responses
"Sample size justification is not provided"
Perform the power analysis retroactively and add it to the Methods. Use the effect sizes of similar studies in the literature with G*Power.
"Statistical methods are insufficient for the data"
Perform the normality test, justify your test selection, and add confounding analysis.
"The study lacks a control for multiple comparisons"
Apply a Bonferroni correction or false discovery rate (FDR) control and add this to the Methods.
For writing the Methods section and preparing reviewer responses, request a free consultation.
Where Do People Get Stuck Most in This Analysis?
- You wrote the study design section, but the reviewer says "insufficient detail", and it is unclear what you left out.
- In the statistical analysis subsection, you wrote "performed with SPSS", but this is not enough; test details are requested.
- There is an inconsistency between the Methods and Results sections, but you cannot find where it is.