Essential Medical Statistics

Combining nonoverlap and trend for single-case research: Tau-U.

Objective. To provide clinicians with a brief screening tool to predict accurately which individuals may develop aberrant behaviors when prescribed opioids for chronic pain.

Design.  One hundred and eighty-five consecutive new patients treated in one pain clinic took the self-administered Opioid Risk Tool (ORT). The ORT measured the following risk factors associated in scientific literature with substance abuse: personal and family history of substance abuse; age; history of preadolescent sexual abuse; and certain psychological diseases. Patients received scores of 0–3 (low risk), 4–7 (moderate risk), or ≥ 8 (high risk), indicating the probability of their displaying opioid-related aberrant behaviors. All patients were monitored for aberrant behaviors for 12 months after their initial visits.

Results.  For those patients with a risk category of low, 17 out of 18 (94.4%) did not display an aberrant behavior. For those patients with a risk category of high, 40 out of 44 (90.9%) did display an aberrant behavior. The authors used the c statistic to validate the ORT, because it simultaneously assesses sensitivity and specificity. The ORT displayed excellent discrimination for both the male (c = 0.82) and the female (c = 0.85) prognostic models.

Conclusion.  In a preliminary study, among patients prescribed opioids for chronic pain, the ORT exhibited a high degree of sensitivity and specificity for determining which individuals are at risk for opioid-related, aberrant behaviors. Further studies in a variety of pain and nonpain settings are needed to determine the ORT's universal applicability.

/pdf/predicting-aberrant-behaviors-in-opioid-treated-patients-2mpgboaast.pdf

Predicting aberrant behaviors in opioid-treated patients: preliminary validation of the Opioid Risk Tool.

2 Comparison of multiple independent samples (One-factorial design) 2 2.1 Kruskal and Wallis test . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 2.2 Kruskal-Wallis – post-hoc tests after Nemenyi . . . . . . . . . . . . . . . . 3 2.3 Examples using posthoc.kruskal.nemenyi.test . . . . . . . . . . . . . 4 2.4 Kruskal-Wallis – post-hoc test after Dunn . . . . . . . . . . . . . . . . . . 6 2.5 Example using posthoc.kruskal.dunn.test . . . . . . . . . . . . . . . . 7 2.6 Kruskal-Wallis – post-hoc test after Conover . . . . . . . . . . . . . . . . . 8 2.7 Example using posthoc.kruskal.conover.test . . . . . . . . . . . . . . 8 2.8 Dunn’s multiple comparison test with one control . . . . . . . . . . . . . . 9 2.9 Example using dunn.test.control . . . . . . . . . . . . . . . . . . . . . 10 2.10 van der Waerden test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 2.11 Example using vanWaerden.test . . . . . . . . . . . . . . . . . . . . . . . 12 2.12 post-hoc test after van der Waerden for multiple pairwise comparisons . . 12 2.13 Example using posthoc.vanWaerden.test . . . . . . . . . . . . . . . . . 12

The Pairwise Multiple Comparison of Mean Ranks Package (PMCMR)

Background Patients with vasculitis induced by the hepatitis C virus (HCV) have reduced levels of regulatory T cells (Tregs). Resolution of HCV infection correlates with cure of vasculitis and the recovery of Treg levels. We reasoned that interleukin-2, a cytokine that promotes Treg survival and function, could be beneficial for patients with vasculitis that is resistant to HCV therapy. Methods We investigated the safety and immunologic effects of the administration of low-dose interleukin-2 in a prospective open-label, phase 1–phase 2a study. Ten patients with HCV-induced vasculitis that was refractory to conventional antiviral therapy, rituximab therapy, or both and who were not receiving glucocorticoid or immunosuppressant therapy received one course of interleukin-2 (1.5 million IU per day) for 5 days, followed by three 5-day courses of 3 million IU per day at weeks 3, 6, and 9. Both the safety of the treatment and its effectiveness were evaluated, the latter by monitoring the Treg response and the cl...

https://www.nejm.org/doi/pdf/10.1056/NEJMoa1105143

M. F. Fuller

Papers

Practical Nonparametric Statistics; Nonparametric Statistical Inference