RESEARCH: Process and Art Diana Battistutta Statistical Epidemiologist Research Methods Group CRICOS No. 00213J
OBJECTIVES • Perspectives on a research question • the why of our research • paradigms, methodologies… • ‘Process’ of research • design: the plan… what, how should we collect data? • methods: detailed ‘recipe’ to match the design – control / causality • ‘Art’ of research • beyond the plan: the unanticipated limitations • interpreting results in light of plan and limitations • Evaluating research – own & others’ CRICOS No. 00213J
Example Ultraviolet (UV) radiation & Skin Cancer • Established causal relationship (now) • Early 1980’s was a different story • Research history…
Research – why? • No knowledge or no preconceived expectations • exploring • patterns • let the data speak, speculating for further validation • Current knowledge seems: • inadequate • ambiguous • incorrect • Expectations - questions needevidence-based answers: • primary data (design control) • secondary data (inherited design…less control) CRICOS No. 00213J
Perspectives & Paradigms • Research is about inquiry incrementing knowledge • Approach to research depends on • knowledge so far accumulated & expectations (if any) • what aspect needs to be incremented • Knowledge is about describing variation in structured way • What’s different? What’s similar? Both are important ! • Emphasis may be on • micro-level = individual differences & similarities – totality of experience • macro-level = typical group differences & similarities – common experience… CRICOS No. 00213J
Perspectives & Paradigms INTERPRETATION – THE ‘STORY’ major (important) sources of difference relative to background variationpatterns, themes prioritised ONE (most likely) EXPLANATION, evidence-based CRICOS No. 00213J
Perspectives & Paradigms Two major philosophical perspectives • QUALITATIVE: the whole • Individual experiences contribute to a holistic perspective on a question: ‘setting the scene’ for the experience • Words and a story of the whole experience • QUANTITATIVE: a part • Individual experiences contribute to a description of a typical group experience: ‘typical’ patterns • Numbers and a story to answer particular questions about the experience CRICOS No. 00213J
Perspectives & Paradigms Philosophical Stance Naturalistic Paradigm (+) No expectations Inductive reasoning perspective (from one experience to general) Various ideological perspectives Various traditions of inquiry Positivist Paradigm Definite expectations (hypotheses) Deductive reasoning perspective (from many to one statement) Popper’s Theory of Falsification Fisher vs Neyman-Pearson perspectives on hypothesis-testing Various experimental & observational designs
Perspectives & Paradigms Philosophical Stance Naturalistic Paradigm (+) No expectations Inductive reasoning perspective (from one experience to general) Various ideological perspectives Various traditions of inquiry Postmodernism Feminist theory Socio-critical theory … Case Study Biography Phenomenology Ethnography Grounded Theory …
Perspectives & Paradigms Philosophical Stance Positivist Paradigm Definite expectations (hypotheses) Deductive reasoning perspective (from many to one statement) Popper’s Theory of Falsification Fisher vs Neyman-Pearson perspectives on hypothesis-testing Various experimental & observational designs Anticipated relationship Experimental control – AEBE Belief models Behaviour models … Randomised controlled trials Cohort studies Cross-sectional studies Case-Control studies Case-series Case description …
Perspectives & Paradigms Philosophical Stance Positivist Paradigm Definite expectations (hypotheses) Deductive reasoning perspective (from many to one statement) Popper’s Theory of Falsification Fisher vs Neyman-Pearson perspectives on hypothesis-testing Various experimental & observational designs Anticipated relationship Experimental control – AEBE Belief models Behaviour models … Randomised controlled trials Cohort studies Cross-sectional studies Case-Control studies Case-series Case description … Spectrum?
Perspectives & Paradigms Conceptual Models Useful for focus Sometimes based on existing theoretical frameworks - used ‘as is’ - adapted = limited, extended, changed - grounded in literature, contextual knowledge Sometimes just a ‘mind-map’ of our research boundaries CRICOS No. 00213J
Conceptual Models – no information • sometimes, the research is all about developing the ‘first’ conceptual model • conceptual models can be what we think is true at the moment to set the scene for next round of research – refinement is constant • conceptual models can be based on strongly-evidenced theoretical perspectives – refinement not an aim CRICOS No. 00213J
Conceptual Models – an experiment UV-A mouse DNA mutation rate UV-B UV-C AEBE ! CRICOS No. 00213J
Conceptual Models – an observational study age naevi hours sun exposure Melanoma status protective clothing CRICOS No. 00213J
Conceptual Models – an observational study age family history hours in sun Melanoma status CRICOS No. 00213J
Why are so many more persons in Queensland getting melanoma than in other Australian states, or the world? • What’s different about Queensland, or its population?
Ecological studies – summary data Queensland Melanoma Incidence Geographical Location (latitude) Climate and population differences to explore further
What’s different about Queensland, or its population? • Queensland has - a hotter, sunnier climate, - beaches • People - enjoy a more outdoor lifestyle - wear less clothing - have more ‘leathery’ skin - some get melanoma, some don’t 2 1 3 Could it be that the sun is a factor in melanomarisk?
1. The sun … • Sun = radiation spectrum - ultraviolet • How does the radiation exposure of Queenslanders differ? UVC UVB UVA 200 280 320 400 We have extremely high UV radiation most of year. Radiation can cause cell change. In what human tissue can UV cause damage, and what doses does it take?
2. Melanoma … • Cancer = melanin cells go ‘haywire’, finally metastasising • Melanin = pigment = concentrated in moles (naevi) How susceptible are melanin cells to radiation damage? Could naevi be a marker for melanoma risk in individuals?
3. Risk factors in Queenslanders… • How are those with melanoma coping? What do they need? • cancer support services • access to health services • informing health policy and health interventions • What characteristics & exposures are associated with cancer? • what distinguishes those with melanoma? • Exposures to UV • outdoor lifestyle (occupation, times of day, covering of body) • Propensity to skin damage • susceptibility (skin pigment, family history of melanoma)
Precise Research Questions…Expectations • Does daily-applied SPF15+ sunscreen over five years reduce the incidence of skin cancer in a group when compared to usual sunscreen application over the same period in a comparison group? • an experiment at community level • carefully-defined outcome and intervention • only ethical if substantial pre-experimental knowledge supports experimentation • To get to this point, requires decades of knowledge-gathering at various levels • extant data revisited, • holistic perspectives from hearing the experiences of individuals, • conceptual postulates defined and tested using laboratory experimentation on molecules/ cells/ tissue/ people, • community surveys, experts coming together, etc.
THE ISSUE Homelessness THE PARTICULAR QUESTION / FOCUS What does it mean to be homeless in Brisbane? DATA COLLECTION Purposive snowball sample of homeless persons Postmodernist perspective Ethnography DATA ANALYSIS QUALITATIVE ANSWER TO QUESTION CRICOS No. 00213J
THE ISSUE Homelessness THE PARTICULAR QUESTION / FOCUS Is it related to mental health status? Observational survey of mental health profile and other characteristics of a sample of homeless persons in Brisbane DATA COLLECTION Comparison of rate of mental illness in this group to general Queensland population to see if higher that expected DATA ANALYSIS QUANTITATIVE - observational ANSWER TO QUESTION CRICOS No. 00213J
THE ISSUE Homelessness Mental health quality of life (QoL) of homeless people is improved when they have access to drop-in centres that include a psychological support service cf standard drop-in centres. THE PARTICULAR QUESTION / FOCUS Experimental study, group of homeless persons, randomised to attend specific drop-in centre – with or without psych support. MCS scale of SF-36 questionnaire: pre & post 3 months. DATA COLLECTION DATA ANALYSIS Hypothesis is that mean QoL higher in group with psych support – an ANOVA statistical test QUANTITATIVE - experiment ANSWER TO QUESTION CRICOS No. 00213J
time change? groups comparison procedures how many? people quality outcome who? data collection measure’t data management QUESTION Hypotheses DESIGN choices aims ANALYSIS assumptions calculations interpretation REPORT confidence clarity comprehension * CRICOS No. 00213J
What is your topic area? • What is likely to be the focussed question of main interest to you? • Is it likely to be a qualitative or quantitative approach that will better suit? Or mixed?
This is part of a bounded area – extrapolate how you think the pattern continues so that the two ends meet… CRICOS No. 00213J
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INAPPROPRIATE PERSPECTIVES CAN LEAD TO INCORRECT CONCLUSIONS We all have prejudices, limited vision, expectations that get in the way of objectivity… CRICOS No. 00213J
BIAS • Incorrect ‘story’ (conclusions) • More than one ‘story’ (explanation) • No evidence for decision paths chosen CRICOS No. 00213J
RIGOUR (no bias) • CONFOUNDING BIAS COMPETING EXPLANATIONS • INFORMATION BIAS MEASUREMENT DIFFERENTIALS • SELECTION BIAS (qualitative studies too?) SAMPLE DOES NOT REFLECT POPULATION BEING INFERRED – [motivation, access, demographics, health etc] CRICOS No. 00213J
Design = Minimising Bias 1. ELIMINATE COMPETING SOURCES – ultimate control • Restriction • Homogenizing, pooling • Randomizing • BEFORE data collection 2. MEASURE COMPETING SOURCES - worry • Know of & quantify ALL sources of variation • Account for statistically • AFTER data collection EXPERIMENTAL DESIGN OBSERVATIONAL DESIGN CRICOS No. 00213J
ART – the bits that need your input! Your ability to be confident & evidence-based in the non-formulaic parts of research will earn you the qualification ‘researcher’. The rest is just hard work. • Identify the risks – be pessimistic and prepared • Make evidence-based decisions, and stick to them CRICOS No. 00213J
ART – the bits that need your input! • Identify and mitigate risks of bias creeping in to any aspect of your design, execution, analysis, interpretation, reporting, and dissemination of results • Aspire to best-practice research but document what will (definitely) go wrong or be done with need for short-cuts. Be transparent about these • Credible research is thoroughly-reported research, not perfect research • Speculation is permissible and welcome, as long as it is reported as such CRICOS No. 00213J
STUDIES within THE STUDY • Pilot studies – procedures to better-inform main study design • Measurement or procedural calibration (validation) • Machines, materials, researchers, participants • Sensitivity to assumptions along the way • Machines, materials, researchers, participants (again!) • Exploratory & confirmatory analyses – cannot be based on the same data CRICOS No. 00213J
REPORTING TO BEST-PRACTICE GUIDELINES CAN HELP Reporting Guidelines for Specific Study Designs CONSORTrandomised, controlled trials STARD studies of diagnostic accuracy QUOROM systematic reviews & meta-analyses STROBE observational studies in epidemiology MOOSE meta-analyses of observational studies BMJ et al qualitative study designs CRICOS No. 00213J
GOOD RESEARCH METHOD • Read widely and critically… history is important – ‘old’ research sets context and dictated directions of current research (not always correctly) • Read beyond your boundaries to know where to set your boundaries; nothing is truly wasted • Just because others have published a certain approach does not make it correct or current – read critically • Understand the basic differences in the philosophies underpinning your research approaches of choice – inductive vs deductive thinking is a great start • Understand that there is NEVER complete objectivity in research – perspectives need to be declared in all research CRICOS No. 00213J
GOOD RESEARCH METHOD • Understand that at the end of it all, you will be reporting to your original design - NOT changing your research question to match what you find !!! • Negative studies are just as important as positive studies (publication bias is rife). You do NOT need to do another study. • Analysis packages cannot ‘do’ the analysis for you – qualitative OR quantitative, but… • Driving them is easy when you have a good idea where you want to go – analytical plans are a MUST • Do an analysis unit close to the time you will be analysing your data. “Use it or lose it”. CRICOS No. 00213J