Science without sense…double nonsense

Píldoras sobre medicina basada en pruebas

Epidemiology

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  1. The scientific method. Methodology of investigation.
    The Ten Commandments.
  2. Frequency measures. Ratio. Porportion. Rate.
    About chalk and cheese.
  3. Causality.
    From the triangle to the pie.
  4. Incidence rate. Incidence rate ratio.
    Some new come and some others go.
  5. Association measures. Risk. Relative risk (RR). Risk ratio. Relative risk reduction (RRR). Absolute risk reduction (ARR). Number needed to treat (NNT).
    They do not trick you with cheese.
  6. NNT’s confidence interval.
    The tribulations of an interval.
  7. Other impact numbres. Impact number in exposed. Impact number in cases. Impact number in exposed cases.
    Simplifying the impact.
  8. Association measures. Odds. Odds ratio.
    The one with the foreign name.
  9. Berkson’s falacy.
    Generalizations are hazardous.
  10. Choosing between risk ratio and odds ratio.
    The ratio’s trap.
  11. Hazard ratio. Cox regression.
    The hare and the tortoise.
  12. Confounding (I). Confounding variable. Confounding factor.
    The backdoor.
  13. Confounding (II). Pairing. Cohort studies. Adjusting in case-control studies.
    Birds of a feather flock together.
  14. Confounding (III). Pairing. Matching. Case-control studies.
    A matter of pairs.
  15. Effect modifiers. Interaction. Standardized risk ratio.
    Ménage à trois.
  16. Sampling techniques. Simple random sampling. Stratified random sampling. Non-randomized sampling techniques. Finite sample correction.
    An important decision.
  17. Classification of epidemiological studies.
    Which family you belong?
  18. Cross-sectional studies. Association cross-sectional studies.
    That’s not what it seems to be.
  19. Ecologic studies. Ecological fallacy. Association.
    Chocolate’s fallacy
  20. Cohort studies. Impact measures. Incidence’s difference. Exposed attributable fraction. Population attributable fraction. Impact numbers.
    One about Romans.
  21. Case-control studies. Odds ratio. Selection bias.
    From the hen to the chicken.
  22. Case-crossover studies.
    You make your bed, you lie in it.
  23. Hybrid designs. Cohort nested case control study. Case cohort study.
    Togeteher but not in each other’s pockets.
  24. Randomized clinical trial. Intervention group. Control group. Placebo. Randomization. Follow-up. Per protocolo analysis. Intention to treat analysis. Parallel clinical trial. Equipoise..
    King of Kings.
  25. Types of clinical trials. Cross-over clinical trial. Factorial clinical trial. Sequential clinical trial. Cluster allocation trial. Community trial.
    The other sides of the King.
  26. Crossover clinical trials analysis.
    Don’t get your wires crossed.
  27. Equivalence and non-inferiority trials. Equivalency limits. Clinical relevance. Statistical significance.
    The consolation of not being worst.
  28. Cluster clinical trial.
    The gregarious one.
  29. Factorial clinical trial.
    More than one rooster per pen.
  30. Crossover clinical trial.
    Twisting parallels.
  31. Adaptive clinical trials.
    The chameleon.
  32. Pilot studies.
    About pilots.
  33. Run-in phase. Washout period. Clinical trials.
    Steady… ready…
  34. Re-randomization.
    Regular customers.
  35. Intention to treat analysis.
    Intention is what matters.
  36. Contingency tables. Cross-sectional studies. Cohort studies. Case-control studies. Cumulative incidence. Incidence density.
    The table.
  37. Masking. Single-blinded. Double-blinded. Triple-blinded.
    To see well you must be blind.
  38. Randomization. Simple randomization. Block randomization. Stratified randomization.
    The necessity of chance.
  39. Composite outcome variables.
    Strength through unity.
  40. Random error. Systematic error.
    The fairground shotgun.
  41. Errors. Random error. Sistematic error. Selection bias. Information bias.
    To err is human.
  42. Preventive trial biases. Participation bias. Lead time bias. Length time bias.
    The sun is not hurried by early risers.
  43. Diagnostic tests (I). Sensitivity. Specificity. Positive predictive value. Negative predictive value. Likelihood ratio. Pre-test probability. Post-test probability. Probabilities ratio.
    All that glitters is not gold.
  44. Diagnostic tests (II). Sensitivity. Specificity. False positive. False negative. ROC. Cutoff.
    The guard’s dilemma.
  45. Diagnostic tests (III). Screening. Early diagnostic. Primary prevention.
    Prevention not always is better.
  46. Diagnostic tests (IV). Sensitivity. Specificity. Positive predictive value. Negative predictive value. Screening. Prevalence calculation.
    The imperfect screening.
  47. Diagnostic tests (V). Diagnostic threshold. Treatment threshold.
    Crossing the threshold.
  48. Diagnostic tests (VI). Accuracy index. Youden’s index. Number needed to diagnose. Number needed to misdiagnose one.
    The turn of the screw.
  49. Diagnostic tests (VII). Diagnostic odds ratio.
    A never-ending story.