Epidemiology statistical analysis

This monograph is based upon papers and discussion from the technical review on phencyclidine which took place on May 7-9, 1985, at Rockville, Maryland. The review was sponsored by the Divisions of Preclinical Research, Clinical Research, and Epidemiology and Statistical Analysis of the National Institute on Drug Abuse. 

The editor would like to thank the participants, all of whom provided timely and complete reports in their areas of expertise, and Dr. J. Michael Walsh (Division of Clinical Research) and Nicholas J. Kozel (Division of Epidemiology and Statistical. Analysis) who cochaired the Technical Review. Special thanks go to Dr. R. Stanley Burns, who made a major contribution by suggesting suitable clinical investigators. 

National Institute on Drug Abuse Division of Epidemiology and Statistical Analysis Parklawn Building, Room 11A52 5600 Fishers Lane Rockville, MD 20857... 

Hill WJ, Ferguson WS. 1979. Statistical analysis of epidemiological data from a chromium chemical manufacturing plant. J Occup Med 21 103-106. 

Epidemiology analyzes statistical data to deiennine tlie lelationslup between a chemical and tlie exposed populatioa However, positive statistical analysis does not always translate into a cause and effect relationsltip between the chemical and disease in humans. Wlien a cause and effect relationsliip between the chemical and disease has been establislied, hirtlier statistical analysis helps define tlie upper limit of hmnan toxic risk. 

The third component of the FDA CDER is the Office of Surveillance and Epidemiology. This group is responsible for ongoing reviews of product safety, efficacy, and quality. It accomplishes this goal by performing statistical analysis of adverse event data it receives to determine whether there is a safety problem. This office reassesses risks based on new data learned after a drug is marketed and recommends... 

The relation between oseltamivir and adverse behaviors was investigated in a large epidemiological study in Japan in the winter of 2006-2007 and the preliminary results were reported in Japanese oseltamivir had no adverse effects [256. However, the statistical analysis of the results has been criticized, and it has been suggested that a more appropriate analysis shows that the rate ratio of psychiatric adverse reactions to oseltamivir was 1.57 (95% Cl = 1.34, 1.83) [257. Two other studies have since been published. 

Because the epidemiological approach - or at least the statistical analysis that it involves - is theory-fi ee it is prone to many misinterpretations. This can best be illustrated with the findings of a recent study that evaluated the increased crash risk due to a specific color of a car. In other words, does the color of a car affect the likelihood of its getting involved in a crash Furness and his associates (2003) addressed that question by examining the data for 567 crash-involved vehicles in the Auckland region of New Zealand in which at least one of the occupants was either severely injured or killed. They compared the frequencies of different car colors in the crash sample to the frequencies of different car colors in an exposure sample of 588 vehicles traveling on the roads in the same region. The results of their analyses are summarized in Table 17-3. 

In most studies, phytoestrogen intake has been estimated by direct methods that evaluate food intake either by recall (food-frequency questionnaires -FFQs) or by record (food diary), and subsequently by composition databases based on information of this kind. Food-frequency questionnaires are widely administered to subjects involved in epidemiological studies. Their validity and reproducibility is considered sufficient when statistically correlated to data obtained from dietary records (a properly-completed and comprehensive food diary) and from analysis of blood and urine samples (Kirk et ah, 1999 Huang et al, 2000 Yamamoto et al, 2001 Verkasalo et al, 2001). FFQs can be repeated several times a year and may be administered to large populations. Such an approach provides an easy and low-cost method of assessing the... 

There is some USEPA precedent for use of statistical meta-analysis in a regulatory context, including the recent meta-analysis of organophosphate-related acetylcholinesterase inhibition data and meta-analysis of epidemiological studies on effects of 2nd hand tobacco smoke exposure. Warren-Hicks and Moore (1998) provide some discussion of the potential applicability of meta-analysis to ecological risk assessments. 

---