Uniform Case Definition Research Articles

The Need for Standardization of Methods for Worldwide Infant Hearing Screening: A Systematic Review

No uniform case definition presently exists for infant hearing screening programs worldwide especially for minimal hearing loss (HL). This article systematically reviewed the current practices in developing countries for programs aimed at early detection of "disabling" congenital and early-onset HL and found significant variations which undermine comparability of key findings in the reported studies. Implications for the exclusion of minimal HL are explored within the context of the International Classification of Functioning, Disability and Health (ICF) of the World Health Organization and its adapted version for children and youth (ICF-CY). A revised World Health Organization classification that accounts for all categories of HL based on ICF-CY may provide a suitable framework for improved uniformity in reporting standards.

Direct hemoperfusion with polymyxin-B-immobilized fiber columns improves septic hypotension and reduces inflammatory mediators in septic patients with colorectal perforation

Although some studies have reported favorable effects of direct hemoperfusion with polymyxin-B-immobilized fiber columns (PMX) for the treatment of septic shock, few studies have demonstrated the efficacy of PMX in studies with a uniform case definition and without any other blood purification techniques. Fifty-two patients with severe sepsis or septic shock secondary to colorectal perforation were treated with PMX. Hemodynamic alterations and plasma concentrations of endotoxin, interleukin (IL)-1beta, IL-1 receptor antagonist (IL-1Ra), IL-6, IL-8, and IL-10 were evaluated following PMX treatment. We observed a significant reduction in plasma endotoxin in the nonsurvivors immediately after PMX treatment compared to before treatment. Systolic blood pressure was markedly increased and circulating levels of IL-1beta, IL-1Ra, and IL-8 were significantly reduced during a 2-h interval of PMX. Our findings suggested that PMX treatment appears to adsorb endotoxin and also modulates circulating cytokine during a 2-h interval of direct hemoperfusion in septic patients with such condition.

Disaster Events and the Risk of Sudden Cardiac Death: A Washington State Investigation

Psychological distress following disaster events may increase the risk of sudden cardiac death. In 2001, the Nisqually earthquake and the 11 September terrorist attacks profoundly affected Washington state residents. This research investigated the theory that the incidence of sudden cardiac death would increase following these disaster events. Death certificates were abstracted using a uniform case definition to determine the number of sudden cardiac deaths for the 48-hour and one-week periods following the two disaster events. Sudden cardiac deaths from the corresponding 48-hour and one-week periods in the three weeks before the events, and the analogous periods in 1999 and 2000 were designated as control times. Using t-tests, the number of sudden cardiac deaths for the periods following the disaster events was compared to those of the control periods. In total, 32 sudden cardiac deaths occurred in the four counties affected by the Nisqually earthquake during the 48 hours after the event, compared to an average of 22 +/- 3.5 (standard deviation) in the same counties during the control periods (p = 0.02). No difference was observed for the one-week period (94 compared to 79.2 +/- 12.4, p = 0.28). No difference was observed in the number of sudden cardiac deaths in the 48-hours or one-week following the terrorist attacks compared to control periods. A local disaster caused by a naturally occurring hazard, but not a geographically remote human disaster, was associated with an increased risk of sudden cardiac death. A better understanding of the underlying mechanisms may have implications for prevention of sudden cardiac death.

The Neurocognition Deployment Health Study: A Prospective Cohort Study of Army Soldiers

Questions remain regarding the effects of military operational deployment on health. The Neurocognition Deployment Health Study addresses several gaps in the deployment health literature, including lack of baseline health data, reliance on subjective measures of exposure and health variables, prolonged intervals between redeployment and health assessments, and lack of a uniform case definition. The Neurocognition Deployment Health Study uses a prospective cohort design to assess neuropsychological outcomes associated with Iraq deployment. Methods incorporate administration of performance-based neuropsychological measures to Army soldiers before and after Iraq deployment and to nondeployed Army Soldiers assessed during comparable periods of garrison duty. Findings should have the potential to delineate neuropsychological outcomes related to combat theater deployment and to identify potential risk and protective factors related to health outcomes.

Evaluation of tickborne encephalitis case classification in Poland

Central European tickborne encephalitis (TBE) is a viral disease of the central nervous system. Despite a surveillance system for TBE existing in Poland since 1970, there are no standardised case definitions and different diagnostic tests are used in various regions. The purpose of this study was to summarise four years of surveillance data using standardised case definitions. From 1999 to 2002, 607 cases of TBE were reported to Poland's national surveillance system: 386 (63.6%) were males, 331 (54.5%) lived in rural areas, and 186 (30.6%) were between 30 and 50 years old. Of 606 diagnosed cases, 453 (74.7%) had aseptic meningitis, 109 (18.0%) had meningoencephalitis, and 44 (7.3%) had meningoencephalomyelitis. Of the 607 reported cases, 602 (99.2%) could be classified: 153 (25.4%) as confirmed, 343 (57.0%) as probable, and 106 (17.6%) as possible cases. There was a significant difference in classified cases by gender: 28.6% of male cases were classified as confirmed, compared with 19.7% of female cases (chi2= 10.48, p=0.0053). There was a significant difference in case classification by clinical diagnosis: 32.4% of cases with meningoencephalitis were classified as confirmed cases, compared with 24.7% of cases with aseptic meningitis (chi2=11.79, p=0.019). There were also significant differences in the distribution by case definition group across geographical regions. For appropriate monitoring of TBE, a uniform and valid case definition should be used in European countries. With only 25% of reported cases meeting the definition for confirmed cases, there is a need for more complete follow-up and standardised testing of suspect cases.

The Accuracy of Diagnosis of Posterior Uveal Melanoma-Reply

In reply Dr Margo is correct in concluding that findings from clinical trials with rigid selection criteria are not universally applicable to all patients and physicians but only to patients who meet the enrollment criteria established for those trials and to physicians with comparable diagnostic and treatment skills. It also is true that certain types of data from community-based outcomes studies have the potential of being more broadly applicable to the universe of patients with a particular condition. However, because of limitations inherent in the outcomes approach (eg, lack of uniform case definitions and lack of appropriate controls), results from carefully controlled clinical trials will continue to serve as guidelines to practice management for the foreseeable future. The COMS misdiagnosis rate, taken in the context of the results of the study by Dr Margo, illustrates the potential for minimizing misdiagnoses in clinical practice. The quality-control mechanisms in the COMS to

Surveillance of tuberculosis in Europe. Working Group of the World Health Organization (WHO) and the European Region of the International Union Against Tuberculosis and Lung Disease (IUATLD) for uniform reporting on tuberculosis cases.

Consensus-based recommendations have been developed by a Working Group of the World Health Organization (WHO) and the European Region of the International Union Against Tuberculosis and Lung Disease (IUATLD) on uniform reporting of tuberculosis surveillance data in the countries of Europe. A uniform case definition and a minimum set of variables for reporting on each case have been agreed which, when collated on a national basis, will allow comparison of the epidemiology of tuberculosis in different European countries. The Working Group recommends that the case definition includes "definite" cases, where the diagnosis has been confirmed by culture (or supported by microscopy findings in countries where diagnostic culture facilities are not available), and "other than definite cases" based on a clinical diagnosis of tuberculosis combined with the intention to treat with a full course of antituberculosis therapy. Both "definite" and "other than definite" cases should be notified by physicians and, in addition, laboratories should be required to report "definite" cases. The minimum set of variables to be collected on each case of tuberculosis should include: date of starting treatment, place of residence, date of birth, gender, and country of origin, to characterize the patient. Recommended disease-specific variables include: site of disease, bacteriological status (microscopy and culture), and history of previous antituberculosis chemotherapy. The minimum set of variables should be collated on all patients and should be as complete as possible. Additional variables may be collected for individual, local or national purposes, but, in general, completeness of reporting on cases is likely to be better if the information requested is kept to a minimum. Timely reporting of cases is essential for appropriate public health action. Cases should be reported to the health authority at the local and/or regional level within 1 week of starting treatment. Individual-case based information should be reported to the national level by the local or regional level. Feedback to reporters is essential. At the national level, preliminary quarterly reports should be produced and final reports should be published annually.

Microbiology of Community-Acquired Bacterial Pneumonia in Persons With and at Risk for Human Immunodeficiency Virus Type 1 Infection

Bacterial pneumonia is a very common cause of morbidity and mortality among persons with human immunodeficiency virus; however, the microbiologic characteristics (including antibiotic resistance) of bacterial pathogens causing community-acquired pneumonia in this population have not been well characterized or correlated with potentially predictive clinical presentation characteristics. We conducted a retrospective cohort study of all adults known to have or to be at high risk for human immunodeficiency virus infection and hospitalized at San Francisco (Calif) General Hospital from May 1990 through April 1991, with a hospital discharge diagnosis of community-acquired bacterial pneumonia and for whom a medical records review confirmed that this diagnosis met a uniform case definition. Two hundred sixteen eligible patients had one or more hospital admissions meeting the case definition. One or more etiologic pathogens were definitively identified in 75% of cases, with Streptococcus pneumoniae, Haemophilus species, Staphylococcus aureus, and gram-negative bacilli most frequently identified. In patients who had a bacteriologic diagnosis made, 18.6%, 6.8%, and 4.3% had pneumonia caused by pathogens resistant to ampicillin sodium, cefuroxime sodium, or trimethoprim-sulfamethoxazole, respectively. One hundred percent of pathogens isolated were susceptible to ceftazidime. Anemia and use of antibacterial medication at the time of hospital admission were the only independent predictors of ampicillin and cefuroxime resistance. Nearly one fifth of human immunodeficiency virus-associated community-acquired bacterial pneumonias requiring hospitalization were caused by ampicillin-resistant pathogens, and presenting clinical characteristics did not consistently define a subset of patients at lower risk for resistance. In the absence of a diagnostic sputum Gram's stain and pending definitive microbiologic diagnosis, initial empiric therapy should be with a second- or third-generation cephalosporin or possibly trimethoprim-sulfamethoxazole.

Luteal phase deficiency: Effect of treatment on pregnancy rates

Luteal phase deficiency is thought to be a cause of female infertility. Nevertheless, little agreement exists concerning either its diagnosis or its treatment. To address the latter question, we reviewed the English literature and examined the effect of treatment on pregnancy rates. One randomized controlled trial found a statistically insignificant benefit of treatment with progesterone suppositories or oral dehydrogesterone versus no treatment (relative risk 1.9; 95% confidence interval 0.4 to 8.1 ). Three other comparative studies also showed no statistically significant benefit. Case-series reports (before-after studies) claiming benefit failed to account for the effect of regression to the mean. The benefit of treatment for luteal phase deficiency has not been established. Uniform case definitions and randomized controlled trials of adequate power are needed to resolve this problem.

Clinical mumps vaccine efficacy.

From February 5 through April 23, 1982, 110 cases of mumps were reported among 357 students in a middle school in Ashtabula County, Ohio, an overall attack rate of 31%. Vaccine efficacy was calculated using a variety of case definitions, case surveillance systems, and vaccination-status ascertainment methods to evaluate their effects on the estimated vaccine efficacy. From data collected at the school for case ascertainment and vaccination status, clinical vaccine efficacy was initially estimated at 37%. By means of a uniform case definition (parotitis lasting two days or more) and only cases and vaccination status ascertained from parental questionnaires, estimated vaccine efficacy increased to 70%. From secondary attack rates in household members with provider-verified vaccination status, the vaccine efficacy further increased to 85%. This outbreak investigation confirms that the methods used to ascertain cases and determine vaccination status greatly affect estimates of vaccine efficacy. Studies relying solely on school records for case finding and determination of immunization status may provide misleadingly low estimates of vaccine efficacy for mumps vaccine as well as for other vaccines. Appropriate methods demonstrate that mumps vaccine is highly effective and support recommendations for its continued use.

Nonspecific vaginitis: Diagnostic criteria and microbial and epidemiologic associations

Numerous previous studies of nonspecific vaginitis have yielded contradictory results regarding its cause and clinical manifestations, due to a lack of uniform case definition and laboratory methods. We studied 397 consecutive unselected female university students and applied sets of well defined criteria to distinguish nonspecific vaginitis from other forms of vaginitis and from normal findings. Using such criteria, we diagnosed nonspecific vaginitis in up to 25 percent of our study population; asymptomatic disease was recognized in more than 50 percent of those with nonspecific vaginitis. A clinical diagnosis of nonspecific vaginitis, based on simple office procedures, was correlated with both the presence and the concentration of Gardnerella vaginalis (Hemophilus vaginalis) in vaginal discharge, and with characteristic biochemical findings in vaginal discharge. Nonspecific vaginitis was also correlated with a history of sexual activity, a history of previous trichomoniasis, current use of non-barrier contraceptive methods, and, particularly, use of an intrauterine device. G. vaginalis was isolated from 51.3 percent of the total population using a highly selective medium that detected the organism in lower concentration in vaginal discharge than did previously used media. Practical diagnostic criteria for standard clinical use are proposed. Application of such criteria should assist in clinical management of nonspecific vaginitis and in further study of the microbiologic and biochemical correlates and the pathogenesis of this mild but quite prevalent disease.