UniODA vs. Logistic Regression: Serum Cholesterol and Coronary Heart Disease and Mortality Among Middle Aged Diabetic Men

Paul R. Yarnold

Optimal Data Analysis, LLC

The effect of serum cholesterol level on coronary heart disease and mortality was assessed for middle aged diabetic men in a prospective population study.1 Logistic regression was used to test the linear trend over quintiles, yielding estimated p<0.02. However the validity of the estimated Type I error rate is called into question because the minimum expectation for chi-square was violated. UniODA was applied to these data and identified a model yielding moderate classification accuracy (ESS=29.9, exact p<0.0006), which was stable in jackknife validity analysis.

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UniODA vs. Kappa: Evaluating the Long-Term (27-Year) Test-Retest Reliability of the Type A Behavior Pattern

Paul R. Yarnold

Optimal Data Analysis, LLC

This 27-year follow-up investigated long-term stability of Type A behavior (TAB) for 1,180 surviving participants in the Western Collaborative Group Study. The kappa statistic was used to assess reliability among and between self- and Structured Interview-based TAB assessments. Results indicated fair temporal reliability for self-assessments (kappa=0.39), moderate temporal reliability for Interview-assessments (0.24), and low parallel-forms reliability for self and Interview assessments at intake (0.16) or follow-up (0.11). In contrast, for these data UniODA found relatively strong temporal reliability for self-assessments (ESS=50.2), and weak effects for all other estimates (ESS<23.3).

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UniODA vs. Weighted Kappa: Evaluating Concordance of Clinician and Patient Ratings of the Patient’s Physical and Mental Health Functioning

Paul R. Yarnold

Optimal Data Analysis, LLC

This study investigated the concordance between clinician and patient assessments of patient’s physical and mental functioning, made using 4-category ordinal scales, for a consecutive sample of 166 outpatients with rheumatoid arthritis. Weighted kappa isn’t a normed statistic, but the respective weighted kappa statistic obtained for the assessments, 0.39 and 0.30, are believed to reflect fair concordance. Data were also analyzed via confirmatory UniODA models which hypothesized that physician and patient ratings agreed. Findings indicated relatively strong concordance for the physical health ratings (ESS=55.5), and moderate concordance for mental health ratings (ESS=43.3).

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UniODA vs. Chi-Square: Discriminating Inhibited and Uninhibited Infant Profiles

Paul R. Yarnold

Optimal Data Analysis, LLC

Kagan and Snidman investigated processes mediating early reactivity to stimulation in a longitudinal study of 94 four-month-old infants who displayed a combination of either high motor activity and frequent crying, or low motor activity and infrequent crying. Fearful behavior assessed at 9 and 14 months of age was examined in relation to these two infant typologies. Eyeball analysis, which was confirmed statistically using chi-square analysis, revealed that 40% of low motor activity infants displayed “low fear” (which was arbitrarily defined as one or fewer fears) at both 9 and 14 months, versus 0% of high motor activity infants. When UniODA was applied to these data it identified statistically reliable effects at 9- and 14-months: the strongest effect occurred at 14 months. Applying CTA to these data revealed that a multiattribute model wasn’t feasible.

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UniODA vs. Student’s t-Test: Comparing Two Migraine Treatments

Paul R. Yarnold

Optimal Data Analysis, LLC

This study evaluates the number of migraine attacks experienced in a clinical trial of two alternative treatments, for a sample of 67 patients. Several conventional statistical methods were used to compare the number of attacks between treatments, but all of these methods were compromised by violations of their underlying assumptions. Only an exact test motivated by an eyeball spline was revealing. UniODA was used to compare treatments, and identified the latter effect.

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UniODA vs. Chi-Square: Audience Effect on Smile Production in Infants

Paul R. Yarnold

Optimal Data Analysis, LLC

This study compares 10-month-old infant smile status and inter-glance interval for attentive versus inattentive mothers. Statistical analysis by chi-square found no significant effects, while UniODA found that infants with inattentive mothers smile less often, with greater inter-glance intervals.

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