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Research Methodology: An Overview

Research Methodology: An Overview

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Research Methodology: An Overview

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  1. Research Methodology:An Overview Ahmed Mandil, Prof of Epidemiology King Saud University, Riyadh, KSA

  2. Headlines • Health research • Choice of subjects • Data collection methods • Sources of data • Study designs (qualitative, quantitative) • Choice of study design • Health research proposal • Literature review Research Methodology

  3. Health Research • Lab research: applies knowledge of basic sciences towards development of procedures and strategies to prevent, control and understand mechanisms of health-related phenomena • Population-based (field) research: study of distribution, determinants, control measures of health-related phenomena in chosen populations, followed by application of suitable biostatistical techniques which may allow generalization of results • Healthcare-facility (clinical) research: application of epidemiological principles in research based in healthcare facilities, e.g. randomized clinical trials Research Methodology

  4. Research Characteristics • Has a clearly stated question(s) and hypotheses (null, alternative) • Has a specific plan of action • Builds on existent knowledge • Generates NEW data, which answers the original question(s) • Opens horizons for further enquiries and research Research Methodology

  5. Subjects & Data Collection • Selected Units: individuals, groups • Study Populations: cross-sectional, longitudinal • Data collection timing: prospectively, retrospectively, combination • Data collection types: primary, secondary Research Methodology

  6. Study Populations • Cross-sectional: where ONLY ONE set of observations is collected for every unit in the study at a certain point in time, disregarding the length of time of study as a whole (health surveys’ populations are of this type) • Longitudinal: where TWO-OR-MORE sets of observations are collected for every unit in the study, i.e. follow up is involved in order to allow monitoring of a certain population (cohort) over a specified period of time. • Dynamic: gains and loses members Research Methodology

  7. Data Collection Types • Primary: where the investigator is the first to collect the data. Sources include: medical examinations, interviews, observations, etc. Merits: less measurement error, suits objectives of the study better. Disadvantage: costly, may not be feasible. • Secondary: where the data is collected by OTHERS, for other purposes that those of the current study. Sources include: individual records (medical / employment); group records (census data, vital statistics) Research Methodology

  8. Data Collection Sources • Routine systems (e.g. vital statistics: births / deaths; health insurance; communicable diseases) • Surveys (interviews; telephone; mail; self-administered) • Disease registries (hospital / community – based) • Sentinel event recording systems (health; disease; health services) Research Methodology

  9. Study Design: Definition A study design is a specific plan or protocol for conducting the study, which allows the investigator to translate the conceptual hypothesis into an operational one. Research Methodology

  10. Study Designs: Types • Qualitative • Quantitative • Experimental • Observational • Basic • Hybrid • Incomplete Research Methodology

  11. Types of quantitative designs • Observational designs: studies that do not involve any intervention or experiment. • Experimental designs: studies that entail manipulation of the study factor (exposure) and randomization of subjects to treatment (exposure) groups Research Methodology

  12. Observational Designs • Exploratory: used when the state of knowledge about the phenomenon is poor: small scale; of limited duration. • Descriptive: used to formulate a certain hypothesis: small / large scale. Examples: case-studies; cross-sectional studies • Analytical: used to test hypotheses: small / large scale. Examples: case-control, cross-sectional, cohort. Research Methodology

  13. Cross-sectional Studies(Community health studies, surveys) • Characteristics: detects point prevalence; relatively common conditions; allows for stratification; different from surveillance / registers • Merits: feasible; quick; economic; allows study of several diseases / exposures; useful for estimation of the population burden, health planning and priority setting of health problems • Limitations: temporal ambiguity (cannot determine whether the exposure preceded outcome); possible measurement error; not suitable for rare conditions; liable to survivor bias • Effect measure: Odds Ratio + CI Research Methodology

  14. Case - Control Studies • Characteristics: two source populations; assumption that non-cases are representative of the source population of cases. • Merits: least expensive; least time-consuming; suitable for study of rare diseases (especially NCDs) • Limitations: not suitable for rare exposures; liable to selection bias and recall bias; not suitable for calculation of frequency measures. • Effect measure: Odds Ratio + CI Research Methodology

  15. Cohort Studies • Characteristics: follow-up period (prospective; retrospective) • Merits: no temporal ambiguity; several outcomes could be studied at the same time; suitable for incidence estimation • Limitations (of prospective type): expensive; time-consuming; inefficient for rare diseases; may not be feasible • Effect measure: Relative Risk + CI Research Methodology

  16. Cohort Design disease Factor present no disease Study population free of disease disease Factor absent no disease present future time Study begins here Research Methodology

  17. Experimental Designs • Types: Lab experiments; Randomized Clinical trials; Community interventions studies. These types are differentiated by: number of participants and duration • Merits: control of confounders • Limitations: limited generalizability; possibility of unethical randomization; impracticabilityunder some settings Research Methodology

  18. Experimental Design outcome RANDOMIZATION Intervention no outcome Study population outcome Control no outcome baseline future time Study begins here (baseline point) Research Methodology

  19. Choice of Study Design (I) Depends on: • Research Questions • Research Goals • Researcher Beliefs and Values • Researcher Skills • Time and Funds Research Methodology

  20. Choice of Study Design (II) • Status of existent knowledge • Occurrence of disease • Duration of latent period • Nature and availability of information • Available resources • Time constraints Research Methodology

  21. Health Research Proposal Components • Executive Summary • Literature review & rationale • Objectives & hypothesis • Methodology • Ethical considerations • Chronogram • Budget • References • Investigating team Research Methodology

  22. What is a good proposal ? • Credible innovative research question • Meticulously designed research plan • Carefully selected research team • Attractively presenting all of the above, so that it: • Communicates clearly & concisely • Follows a logical outline • Indicates merits and limitations of the plan, but • Makes sure that merits do stand out (for a busy reviewer) Research Methodology

  23. Literature Review • Peer consultation • Databases (search engines: e.g. Pubmed; Medline; Ovid; IMEMR at WHO / EMRO website) • Published literature (scientific journals) • Published literature (electronic journals) • Grey literature (theses: masters / doctoral; reports: ministry of health / social affairs / annual statistics; national census, others) Research Methodology

  24. References • Porta M. A dictionary of epidemiology. 5th edition. Oxford, New York: Oxford University Press, 2008. • Fathallah MF, Fathallah MMF. A practical guide for health researchers. Cairo: WHO, 2004. • Rothman KF, Greenland S, Lash TL. Modern Epidemiology. 3rd edition. Philadelphia: Walter Kluwer, Williams & Wilkins 2008: 100-110. • Gordis L. Epidemiology. 4th edition. Philadelphia, Pennsylvania: Elsevier Science, 2008  • Beaglehole R, Bonita R, Kjellstrom T. Basic epidemiolgy. 2nd edition. Geneva: World Health Organization, 2006 Research Methodology

  25. Thank you for your kind attention Research Methodology