OUTLINE AND GUIDE TO SCANLAN’S RULE PAGE
(Apr. 24, 2009; rev. June 11, 2011)
The Scanlan’s Rule page of this site consists of a main page (which is accessed by clicking on the yellow wording “Scanlan’s Rule”). Because the mechanics of the site sometimes cause that key page to get overlooked, the material on the page is also presented in a sub-page styled “Summary to SR”). An index to that page follows. Two other sub-pages address particular issues in depth or provide related material.
Outline to Main Page
Introduction
A. Clarifying Points
1. Merely Tendencies Though Powerful Ones
2. Theoretical Basis
3. Meaning of Changes
4. One Pattern Implied in the Other
4a. Scale Issues
4b. Subgroup Effects
5. Increasing Representation among Population Experiencing and Failing to Experience an Outcome
6. The Value of Health Disparities Studies
7. A Measure Unaffected by Prevalence
8. Meaning of “Overall Prevalence.”
9. Settings Differentiated Temporally or Otherwise
10. Effects of Lowering Cutoffs on Employment Tests
11. Absolute Differences.
12. Odds Ratios
13. Phi Coefficient
13a. Cohen’s Kappa Coefficient
14. Longevity
15. Gini Coefficient etc.
16. Irreducible Minimums
17. Concentration Index
18. Probit Analysis
19. Case Control Studies
20. Meta-Analyses
B. Illustrations of SR1 and SR2
1. Feminization of Poverty 1
2. Feminization of Poverty2.
3. Racial Differences in Infant Mortality
4. Racial Differences in Adverse Birth Outcomes among Advantaged Groups
5. Whitehall Studies
6. Nordic Health Disparities
7. NCAA’s Proposition 48
8. Terminations from Employment
9. Racial Impact of the Three-strikes Law
10. Studies of Healthcare Disparities Relying on Absolute Differences
11. NHANES Data
12. Pay-for-Performance Programs
Sub-Pages Treating Particular Issues in Depth or Providing Other Relevant Material
1. Semantic Issues sub-page discusses certain technical semantic issues that have some bearing on patterns described in the main Scanlan’s Rule page.
http://jpscanlan.com/scanlansrule/semanticissues.html
2. Employment Tests sub-page addresses whether, considered in light of the points made generally on the Scanlan’s Rule page, lowering a cutoff on a test in fact reduces the disparate impact of the test in a meaningful way.
3. Case Study sub-page uses a case study approach to illustrating some of the issues raised on the Scanlan’s Rule page and its sub-pages. The page is related to the Relative Versus Absolute sub-page of MHD.
http://jpscanlan.com/scanlansrule/casestudy.html
4. Case Study Answers sub-page provides answers to the questions posed.
http://jpscanlan.com/scanlansrule/casestudyanswers.html
5. Subgroups Effects sub-page discusses the way observers mistakenly identify subgroup effects on the basis of the way factors are associate with different proportionate changes in the rates of groups with different base rates without recognizing the extent to which the different proportionate changes are functions of the different base rates or that the group with the larger proportionate decrease in an outcome will tend to have the smaller proportionate increase in the opposite outcome.
http://www.jpscanlan.com/scanlansrule/subgroupeffects.html
6. Feminization of Poverty sub-page addresses the way that increases in the proportion of the population comprised by members of female-headed families are interpreted without recognition that decreases in the prevalence of an outcome will tend to cause groups particularly susceptible to the outcome to comprise a larger proportion of the population experiencing the outcome than they did previously as well as a larger proportion of the population failing to experience the outcome. See Section B1 and B2 the main Scanlan’s Rule page.
http://www.jpscanlan.com/scanlansrule/feminizationofpoverty.html
7. Explanatory Theories sub-page addresses the way that researchers believing they have identified a larger difference between rates in one setting than another may devise explanations for such perceived larger difference, usually without a sound basis for the perception that the difference is larger.
http://jpscanlan.com/scanlansrule/explanatorytheories.html
8. Mortality and Survival sub-page had been an earlier version of what is now the Mortality and Survival page. It is retained solely to refer users of old links to the new page.
http://jpscanlan.com/mortalityandsurvival2.html
9. Immunization Disparities sub-page addresses patterns by which various measures of disparities in immunization and other health care procedures tend to reach different conclusions with attention given to the January 2011 Health Disparities and Inequalities Report of the Centers for Control and Prevention.
http://jpscanlan.com/scanlansrule/immunizationdisparities.html
11. Truncation Issues sub-page, which is related to the Cohort Considerations sub-page
of MHD, discusses why the patterns described in the introduction to the Scanlan’s Rule page may vary when the populations examined are truncated portions of larger populations, as well as reasons why the Solutions approach on MHD is unsuitable in such circumstances. The matter is also treated on the Life Table Illustrations sub-page of the Scanlan’s Rule page.
http://jpscanlan.com/scanlansrule/truncationissues.html
12. Framingham Illustrations sub-page uses information from online calculator of heart attack risks based on the Framingham studies to illustrate the patterns described on the main Scanlan’s Rule page.
13. Life Table Illustrations sub-page uses life table to data to illustrate the predominance of the distributional forces in circumstances where the differences in prevalence in different settings are great, as is invariably the case with regard to mortality when the two settings involve substantially different ages.
http://jpscanlan.com/scanlansrule/lifetableillustrations.html
14. NHANES sub-page uses data from the National Health and Nutrition Examination Survey to illustrate the patterns described on the main Scanlan’s Rule page.
http://jpscanlan.com/scanlansrule/nhanesillustrations.html
15. Illogical Premises sub-page, which is related to the Subgroup Effects sub-page, explains why it is illogical to regard it as somehow normal that two groups with different base rates should experience equal proportionate changes in an outcome rate (given that it is not possible for two groups with different base rates to experience equal proportionate changes in such rates while also experiencing equal proportionate changes in rates of experiencing the opposite outcome).
http://jpscanlan.com/scanlansrule/illogicalpremises.html
16. Representational Disparities sub-page explains why it is not possible to appraise the size of a disparity when solely on the basis of the proportions a group comprises of persons eligible to experience an outcome and of persons who experience the outcome.
http://jpscanlan.com/scanlansrule/representationaldisp.html
17. Statistical Significance SR sub-page explores whether, given that the same properties of normal distributions that underlie the patters described on the Scanlan’s Rule page, a test of statistical significance given unchanged population size would meet the key criterion for an effective measure of the size of difference between outcome rates (i.e.,, that the measure remain unchanged when there occurs a change in overall prevalence akin to that effected by lowering a test cutoff).
http://jpscanlan.com/scanlansrule/statisticalsignifsr.html
18. Comparing Averages sub-page explains why, irrespective of adjustment considerations, the issues discussed generally on the main page affect comparisons of an average of outcome rates for more than one sub-group with another average of outcome rates for more than one sub-group.
http://jpscanlan.com/scanlansrule/comparingaverages.html
19. Meta-Analysis sub-page briefly explains that factors that tend generally to undermine sub-group analyses similarly undermine meta-analyses of effects on dichotomous outcomes.
http://jpscanlan.com/scanlansrule/metaanalysis.html
20. Case Control Studies sub-page page addresses sub-page addresses a fundamental problem with case control studies in that, while one may be able to derive an approximation of the relative risk from such study, one cannot derive the actual rates.
http://jpscanlan.com/scanlansrule/casecontrolstudies.html