Darryl T. Gray

Incidence of Nonarteritic Anteripr Ischemic Optic Neuropathy

Purpose Nonarteritic anterior ischemic optic neuropathy is the most common acute optic nerve disease of adults over age 50 years. This study determined the incidence of acute nonarteritic anterior ischemic optic neuropathy in the circumscribed population of Olmsted County, Minnesota. Methods This was a retrospective study of the incidence of acute nonarteritic anterior ischemic optic neuropathy between 1981 and 1990. The Rochester Epidemiology Project medical records linkage system facilitates identification of the medical records of virtually all Olmsted County residents with a given diagnosis. All cases of acute nonarteritic anterior ischemic optic neuropathy that fulfilled certain inclusion and exclusion criteria were identified. Results Twenty-two cases in 21 patients (11 men and 10 women) were recorded. The crude annual incidence rate was 10.3 per 100,000 individuals (95% confidence interval [CI] = 5.1 to 18.4). When adjusted to the age and sex distribution of the 1990 United States white population, the incidence rate was 10.2 per 100,000 (95% CI=6.5 to 15.6). At diagnosis, the median age was 72 years, mean visual acuity was 20/200 in the affected eye, and the most common visual field defect was an altitudinal deficit (10 cases). Conclusions Although results of this small study should be interpreted cautiously, extrapolation of our findings to the United States white population indicates that nearly 5,700 new cases of acute nonarteritic anterior ischemic optic neuropathy may be expected to occur each year in this group.

Retinal detachment in Olmsted County, Minnesota, 1976 through 1995

Abstract Objective To estimate the incidence of rhegmatogenous retinal detachment (RD) in a geographically defined population and to compare the probability of RD in residents after cataract extraction with the probability of RD in residents who did not have cataract extraction. Design Rochester Epidemiology Project databases were used to perform a retrospective population-based incidence study of RD diagnosed between 1976 and 1995 with cohort analyses of the influence of risk factors on the occurrence of RD. Participants The population of Olmsted County, Minnesota, participated. Main outcome measure Incidence rates of RD adjusted to the age and gender distribution of the 1990 U.S. white population were measured. Results Three hundred eleven incident cases of rhegmatogenous RD were identified. The mean annual age- and gender-adjusted incidence rate of rhegmatogenous RD was 17.9 per 100,000 persons (95% confidence interval [CI], 15.9–19.9). For idiopathic rhegmatogenous RD alone, the mean annual age- and gender-adjusted incidence rate was 12.6 (95% CI, 10.9–14.3) per 100,000 persons. Ten years after phacoemulsification and extracapsular cataract extraction, the estimated cumulative probability of RD was 5.5 (95% CI, 3.4–7.6) times as high as would have been expected in a similar group of county residents not undergoing cataract surgery. Conclusions Cataract surgery is associated with a significantly elevated long-term cumulative probability of retinal detachment.

A cost-effectiveness study of a randomised trial of laparoscopy versus laparotomy for ectopic pregnancy

We compared the cost-effectiveness of therapeutic laparoscopy and open laparotomy for treatment of laparoscopically diagnosed ectopic pregnancy. Clinical outcomes of ectopic pregnancy treatment were based on results of a randomised trial done between 1987 and 1989 at Sahlgrenska University Hospital (Göteborg, Sweden). We estimated costs for inpatient and follow-up care of ectopic pregnancy by the two methods. Observed resource use (eg, procedure duration) was multiplied by 1992 estimates of resource unit cost (eg, cost per minute of laparoscopy time), based on detailed internal cost accounting data from Huddinge University Hospital. By specified criteria, the initial procedure eliminated trophoblastic activity without major complications in 81% (95% CI: 68-90) of 52 laparoscopy patients, versus 95% (85-99) of 57 laparotomy patients. Residual trophoblast or complications were successfully treated in all remaining patients. Mean simulated costs (standard error) for the overall laparoscopy strategy were 28,058 (1780) Swedish kronor versus 32,699 (1080) kronor for laparotomy (p = 0.03). In the baseline simulation and most sensitivity analyses, laparoscopy produced final outcomes equivalent to those of laparotomy at lower costs. As laparoscopic outcomes improve, this newer approach should become increasingly preferable.

Pediatric third, fourth, and sixth nerve palsies: a population-based study.

PURPOSE To determine the population-based incidence and cause of cranial nerve palsies affecting ocular motility in children in the circumscribed population of Olmsted County, Minnesota. METHODS The Rochester Epidemiology Project medical records linkage system captures virtually all medical care provided to Olmsted County residents. By means of this database, all cases of third, fourth, and sixth cranial nerve palsy were identified among county residents less than 18 years of age from 1978 through 1992. Medical records were reviewed to confirm the diagnosis, determine the cause, and document county residency. Incidence rates were adjusted to the age and sex distribution of the 1990 white population in the United States. RESULTS Over this 15-year period, 36 incidence cases of cranial nerve palsy were identified in 35 children in this defined population. The age-adjusted and sex-adjusted annual incidence of third, fourth, and sixth nerve palsies combined was 7.6 per 100,000 (95% confidence interval, 5.1 to 10.1). The most commonly affected nerve was the fourth (36%), followed by the sixth (33%), the third (22%), and multiple nerve palsies (9%). The most common cause was congenital for third and fourth nerve palsy, undetermined for sixth, and trauma for multiple nerve palsies. Although three cases were associated with neoplasia, a cranial nerve palsy was not present at the time of diagnosis in any case. CONCLUSIONS Unlike many institutionally based referral series, our population-based study provides data on the incidence and cause of third, fourth, and sixth nerve palsies in a geographically defined population. In contrast to previous institutionally based series, nearly half the cases were congenital in origin, and in no case did intracranial neoplasia present as an isolated nerve palsy.

Non-randomized evaluations of the outcomes of treatment of pediatric cardiovascular disease

Abstract The randomized controlled clinical trial is generally acknowledged to provide the most scientifically valid evidence of the efficacy of therapeutic interventions compared to results of specified alternatives. While this approach represents the top of a hierarchy of levels of evidence, other study designs may also be appropriate at various stages in the evaluation of therapy. This article describes other study designs which may be used to assess clinical outcomes, namely case reports, case series, intra- and inter-institutional non-randomized cohort comparisons with historical or concurrent controls, and case-control studies. The relative advantages and disadvantages of each approach are reviewed, and illustrations are provided from the literature in pediatric cardiology and related fields.

Textbook in Psychiatric Epidemiology

It has been revised and enhanced to capitalize on the strengths of the first and second editions while keeping it up-to-date with the field of psychiatry and epidemiology. This comprehensive publication now includes chapters on experimental epidemiology, gene-environment interactions, the use of case registries, eating disorders, suicide, childhood disorders and immigrant populations, and the epidemiology of a number of childhood disorders.