Writing Methods-week3.pdf

Dr Nazish Masud Writing the Manuscript Method section Dr Nazish Masud 1 Objectives of the session By end of this session students would be able to, • Identify the main components of the method section • How to effectively write the method section • Familiarize with Quality checklist for the meth...

Dr Nazish Masud Writing the Manuscript Method section Dr Nazish Masud 1 Objectives of the session By end of this session students would be able to, • Identify the main components of the method section • How to effectively write the method section • Familiarize with Quality checklist for the method section • Do’s and don’ts of method section 2 PROPOSAL In Short REPORT In Detail 9/10/2020 Language and tense Future tense – it explains Past tense – it explains what will be done and why what was done why it was it should be done. e.g.: done. e.g.: We will perform..... We performed..... We are going to.... We did... 3 Methods are Actions • Methods propel one toward something or to do a thing • A method is like a cooking recipe • A method is something that is simply ‘followed’ • A method is a series of directions that pre-suppose we already know what we want 4 Recipe style • • • • • • • • • • Study design Settings Participants Study size Variables Data sources/measurements Methods to control bias Quantitative variables Statistical methods Ethical considerations 5 Method section • Usually up to 800 words, can be shorter or longer depending on study design and type. • Presented as headings, 1. 2. 3. Study settings and participants Data collection method including questionnaire Statistical analysis • 3 to 4 paragraphs • Can be without headings as well but information presented is the same order. • Recipe style 6 First paragraph/heading • Study design, setting and participants • • • • Present key elements of study design early in the paper Describe the setting, locations Relevant dates, including periods of recruitment Exposure, follow-up, and data collection (for prospective Cohort) • Give the eligibility criteria, and the sources and methods of selection of participants • Report the sample size and sampling technique 7 Study design • Mention why you have chosen this study design • Remember: Chart Review is NOT a study design ➢ You have to specify the type of study design when you are doing a chart review: - Case Series - Cross-sectional survey - Case Control - Cohort study (retrospective) 8 Revision : Study Design • Observational study: – Case reports/Series 9/10/2020 Mention the type of study design: – Cross-sectional survey – Case Control study – Cohort study • Interventional study: – Experimental study – Clinical Trial 9 Study Area / Setting conducted • Should give some detail as relevant, i.e. 9/10/2020 • Specify the area or setting where the study was – History / background of the institution or department as relevant e.g. type of institution, level of health care facility, government / private 10 Study Subjects – Total number – Mention the Inclusion criteria for selecting the 9/10/2020 • Briefly describe the study population: subjects e.g. • Age / Gender / Educational / Nationality / etc. background (whichever is applicable / relevant) – Mention the Exclusion criteria (if relevant) • For excluding any subjects after being included through the inclusion criteria • May Not be required for cross-sectional studies) • Should NOT be the opposite of the inclusion criteria 11 Sampling methods... Probability Sampling methods: 1. 2. 3. 4. Simple Random sampling Systematic sampling Stratified sampling Cluster sampling Non-probability Sampling methods: 1. Convenience sampling 2. Purposive sampling 3. Quota sampling 12 Sample size calculation • Elements of the calculations: • Variables: based on Primary Outcome variable • Categorical: • Numerical: Proportions (single / two samples) Means (single / two samples) • The prevalence must be taken from the literature and given with references. • Confidence level and Margin of Error OR • Power and significance level (whatever is suitable) 13 nd 2 Heading • Usually in two paragraphs • Data collection • Provide information about data collection instrument • If it was validated, any pilot testing done for validation • Report Cronbach's Alpha • Main variables (Clearly define all outcomes, exposures, predictors, potential confounders, and effect modifiers. Give diagnostic criteria, if applicable) • Mode of data collection ( self , interviewer administered, internet or phone survey etc.) • Data sources/measurement 14 If questionnaire is self-developed • Important to mention all the steps of tool development. • Give references for any sources used in the development • Mention the translation process in detail 5 steps (if translating from another language) • Pilot testing process in detail (sample size, results and changes done after pilot testing) 15 Explain the data collection tool Survey studies • Clearly explain the different sections of the questionnaire. • How the responses were recorded e.g. YES/NO, or Likert scale • If there is scoring mention the scoring criteria and cut off points. • • • • • Chart reviews Describe your variables The independent and dependent If any cutoff was used, e.g. BP labeled high if > so and so range. Missing data Any measurements if done or lab samples 16 Chart reviews cont.., • Selecting, extracting, and synthesizing data • Explain the follow-up time, • If diagnosis , operational definition used can be mentioned here e.g. • If the outcome breast cancer, then classification used based on the international criteria. REF • DON’T forget referencing here 17 Example 18 Example (chart review) 19 nd 2 paragraph continued • Bias occurs when “systematic error [is] introduced into sampling or testing by selecting or encouraging one outcome or answer over others” • Describe comparability of assessment methods if there is more than one group • e.g. in case control the details of matching criteria for cases and controls. • Also random sampling controls the bias • In experimental studies blinding of investigators and randomization of groups etc. • Sample size relation to bias 20 rd 3 Para / Statistical methods 1. Specify the statistical software package(s) and versions used 2. Describe statistical methods with enough detail to enable a knowledgeable reader with access to the original data to judge its appropriateness for the study and to verify the reported results. 3. Descriptive and inferential statistics 4. Mention the confidence intervals and P values as set 21 Descriptive statistics Mention how the descriptive statistics are presented: • Numerical variables (e.g. Age, Lab measurements, Physical measurements, etc.): as Mean + SD or Median and Inter-quartile Range (for skewed data) • Categorical variables ( e.g. Gender, Disease status, Exposure to risk factor, etc.) as frequencies (%) 22 Inferential Statistics • Types and names of the tests e.g. • • • • • Chi square T –test ANOVA Regression analysis Correlation etc • Mention the scoring cut off points in cases of Likert scales used or questionnaires which needed scoring. 23 Confidence interval 95% Confidence Interval • There is 95% probability that the true parameter is within the calculated interval • Thus, if we repeat the sampling procedure 100 times, the above statement will be: o correct in 95 times (the true parameter is within the interval) o wrong in 5 times (the true parameter is outside the interval) 24 Epidemiological Measures of Association To determine the Association between Risk factor and Disease (Outcome): • Case Control studies: Odds Ratio • Cohort Studies: Relative Risk / Attributable Risk Prognostic studies: • Clinical Trials: Number Needed to Treat Diagnostic studies: • Screening: Sensitivity / Specificity / Positive and Negative Predictive values 25 Ethical issues • Studies involving human subjects / medical records –issues of confidentiality, autonomy • Storage of questionnaires, accessibility to personal information 26 ICMJE Guidelines • A small group of general medical journal editors and representatives of selected related organizations working together to improve the quality of medical science and its reporting • Section by section guide what to put where • The minimum requirements needed http://www.icmje.org/recommendations/browse/manuscriptpreparation/ 27 Guidelines • Reporting guidelines are simple, structured tools for health researchers to use while writing manuscripts. They provide minimum lists of information needed • Guidelines are more than just some thoughts about what needs to be reported 28 Benefit for end-users • • • • Understood by a reader, Replicated by a researcher, Used by a doctor to make a clinical decision, and Included in a systematic review. 29 Reporting Guidelines • Reporting guidelines have been developed for different study designs • CONSORT for randomized trials • STROBE for observational studies, • PRISMA for systematic reviews and meta-analyses • STARD for studies of diagnostic accuracy • http://www.strobe-statement.org/?id=available-checklists • COREQ for qualitative studies • Good sources for reporting guidelines are the EQUATOR Network and the NLM's Research Reporting Guidelines and Initiatives. • http://www.icmje.org/recommendations/browse/manuscriptpreparation/preparing-for-submission.html 30 Strobe checklist items • Describe all statistical methods, including those used to control for confounding • Describe any methods used to examine subgroups and interactions • Explain how missing data were addressed • If applicable, describe analytical methods taking account of sampling strategy • Describe any sensitivity analyses 32 Strobe checklist for all observational studies 33 Summary Methods section • Should describe how the work was performed • Another investigator can duplicate the work based on the methods section • Operational definitions of important terms • Units of measurement for physical / laboratory measures • State the order / sequence that the activities were carried out 34 Tip • Start the writing • Read articles similar to your study design and type published in good journals “it’s always a good idea to look at good examples for inspiration” • Start working on the checklist depending upon your study design. 35 Key to writing • Writing is an art, there’s NO shortcut • Admit it is difficult BUT, 36 37