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At least 19 recordsLinked to original sources
PubMed1980

Case definition and case identification in psychiatric epidemiology: review and assessment.

Psychiatric epidemiology has advanced considerably since early studies of hospital populations. The direction of this advance has been away from the study of populations of hospital psychiatric patients towards the study of psychiatric disorder in general practice and the community as a whole. Just as the populations under study have different defining characteristics, so have the individuals who comprise them. Psychosis becomes less and less common at greater distances from the hospital patient, and in the community the epidemiologist is faced with large numbers of respondents who present with fewer, minor and non-specific symptoms. In this review, we present evidence to indicate that concepts of case definition and case identification are insufficiently advanced so far, and are still rooted in ideas derived from hospital psychiatry. Foremost among these is an exclusive preoccupation with diagnosis and symptoms. We suggest that this may be inadequate for the study of non-psychotic disturbance in the community, and discuss other models of case definition, encompassing personality and social functioning as well as psychiatric symptomatology.

Ambulatory Care↗
PubMed1997

People with intellectual disability in general practice: case definition and case finding.

In a general practice database containing data on 62,000 patients, those with intellectual disability (ID) were traced. Health problems in this database were recorded according to the International Classification of Health Problems in Primary Care (ICPC) code. By using selected codes, 318 people with ID (0.65% of the study population) were found; the sample contained nearly as many false positives. Adding up the percentage of people with ID living in residential facilities, the total prevalence of people with ID was estimated as 0.82%. Documentation on the cause and level of ID was available in about half of the cases. The demographic characteristics of the people with ID were significantly different from the general population: there was a higher percentage of males and a lower percentage of people over 50 years of age among those with ID. Information about the use of home care was virtually non-existent in the general practice data. The results are compared with those of other studies. The discussion deals with reasons for complete documentation of cases with ID in general practice and the role of the general practitioner in health care supply to people with ID.

Adult↗
PubMed1993

Impact of the expanded AIDS surveillance case definition on AIDS case reporting--United States, first quarter, 1993.

On January 1, 1993, the acquired immunodeficiency syndrome (AIDS) surveillance case definition for adolescents and adults was expanded beyond the surveillance definition published in 1987 (1) to include all human immunodeficiency virus (HIV)-infected persons with severe immunosuppression (< 200 CD4+ T-lymphocytes/microL or a CD4+ T-lymphocyte percentage of total lymphocytes of < 14), pulmonary tuberculosis (TB), recurrent pneumonia, or invasive cervical cancer. This report reviews AIDS surveillance reports CDC received from local, state, and territorial health departments during the first quarter of 1993 and summarizes the impact of the changes in the AIDS surveillance case definition.

AIDS-Related Opportunistic Infections↗
PubMedDate not supplied

Idiopathic environmental intolerance: case definition issues.

Case definitions of the same phenomenon may be different for different purposes. Case definitions usually become more specific over time as more information about the condition becomes available. Idiopathic environmental intolerance is one of many labels for a heterogeneous group of conditions in which subjects describe multiple symptoms that are attributed to exposure to extremely low doses of common chemicals. Dr. Kreutzer presents issues in case definition for clinical purposes and for population-based studies, and makes recommendations for the clinician and for the public health investigator.

Dose-Response Relationship, Drug↗
PubMed1992

A simplified surveillance case definition of AIDS derived from empirical clinical data. The Clinical AIDS Study Group, and the Working Group on AIDS case definition.

A clinical AIDS case definition is needed for surveillance in countries where the CDC case definition is not practical. To derive such a definition, we compared 110 HIV-seropositive and 135 randomly selected HIV-seronegative adult medical-ward inpatients in Brazil. Multivariate analysis of clinical signs and symptoms and simple diagnoses resulted in a discriminant function with sensitivity of 89% and specificity of 96% in predicting for AIDS. These data were the empirical basis for a clinical definition of AIDS in adults drafted in a Caracas, Venezuela, workshop sponsored by the Pan American Health Organization. The revised "Caracas" definition presented here requires a positive HIV serology, the absence of cancer or other cause of immunosuppression, plus > or = 10 cumulative points, as follows: Kaposi's sarcoma (10 points); extrapulmonary/noncavitary pulmonary tuberculosis (10); oral candidiasis or hairy leukoplakia (5); cavitary pulmonary/unspecified tuberculosis (5); herpes zoster < 60 years of age (5); CNS dysfunction (5); diarrhea > or = 1 month (2); fever > or = 1 month (2); cachexia or > 10% weight loss (2); asthenia > or = 1 month (2); persistent dermatitis (2); anemia, lymphopenia, or thrombocytopenia (2); persistent cough or any pneumonia except TB (2); and lymphadenopathy > or = 1 cm at > or = 2 noninguinal sites for > or = 1 month (2). This definition has a sensitivity of 95% and a specificity of 100% (91% without HIV serology) when applied to the Brazilian patients in this study. The Caracas definition has been adopted by Brazil, Honduras, and Surinam, and is in validation elsewhere. The use of a reasonably sensitive and specific case definition commensurate with available diagnostic resources should facilitate AIDS surveillance in developing countries.

Acquired Immunodeficiency Syndrome↗
PubMed1981

Infective endocarditis: an analysis based on strict case definitions.

Strict case definitions were applied to 123 clinically diagnosed cases of infective endocarditis. Cases were categorized as definite (19), probable (44), or possible (41) endocarditis or were rejected (19). Compared to other published studies, our patients had an advanced mean age (57), high incidence of underlying valvular disease (66%), short mean duration of symptoms (27 days), and 15% mortality, the lowest reported for a large series. Most cases were caused by viridans streptococci, Staphylococcus aureus, or enterococci; Enterobacteriacae were absent, and negative cultures infrequent (5%). Subgroups included nosocomial endocarditis (13%), usually with underlying valvular disease and invasive procedures; prosthesis endocarditis (12%); and cases requiring cardiac surgery (18%). Deaths were caused by heart failure, neurologic events, or superinfection. Strict definitions are useful in managing suspect cases, and are essential in comparing clinical studies. Early recognition and treatment should be the focus of efforts to reduce mortality from endocarditis.

Adolescent↗
PubMed1994

Update: impact of the expanded AIDS surveillance case definition for adolescents and adults on case reporting--United States, 1993.

During 1993, local, state, and territorial health departments reported 103,500 acquired immunodeficiency syndrome (AIDS) cases among persons aged > or = 13 years in the United States, an increase of 111% over the 49,016 reported in 1992 (Figure 1). This increase resulted from the expansion of the AIDS surveillance case definition in 1993*; in comparison, the number of cases based on the preexisting case definition decreased slightly. This report summarizes characteristics of persons reported with AIDS in 1993, compares these findings with data from 1992, and describes the impact of the change in the AIDS surveillance definition on AIDS case reporting.

Acquired Immunodeficiency Syndrome↗
PubMed1992

Effect of the revised CDC case definition of AIDS on the number of AIDS cases in the Sydney AIDS Prospective Study.

We sought to evaluate the potential impact of a proposed revision in the case definition of acquired immunodeficiency syndrome (AIDS) (from a clinical case definition to one also including subjects with HIV infection who have an absolute number of peripheral CD4+ cells of less than 200 x 10(6)/L) among 512 HIV-seropositive homosexual/bisexual who were reviewed between 1984 and 1991. According to the current case definition, 151 (30%) of 512 at-risk subjects developed AIDS between 1984 and August 1, 1991. Of the 361 at-risk subjects who were not classified as AIDS by the current definition, 47 (13%; 95% CI 9-17%) were classified as AIDS according to the revised definition. The median time to development of AIDS according to the revised definition was 288 weeks and that according to the current definition was 338 weeks. Data on clinical status were available for 34 of the new cases at the time of their diagnosis according to the proposed case definition: 16 (47%) of these were asymptomatic, 10 (29%) had persistent generalised lymphadenopathy and eight had minor infectious diseases. Of the 151 cases diagnosed according to the current definition, 78 (52%) had an antecedent CD4+ cell count that met the criteria for AIDS under the revised definition a median of 59 weeks before their diagnosis according to the current definition. These data indicate an appreciable increase in the number of cases of AIDS in this cohort when the revised case definition was applied. These findings have important implications for the surveillance, and for the clinical monitoring and treatment, of patients with HIV disease in Australia.

Acquired Immunodeficiency Syndrome↗
PubMedDate not supplied

Case definition and power in case-control studies.

A narrow case definition can lead to greater in clarity in case-control studies, but it can also lead to either a gain or a loss in the power of statistical tests. Under plausible assumptions, the loss of power can be in excess of 30 per cent, and the gain can be in excess of 50 per cent. If at least one third of the total study size consists of narrowly defined cases, the loss of power will often be negligible, whereas the gain can be substantial.

Dose-Response Relationship, Radiation↗
PubMed2000

[Comparison of chest CT findings between suspected and definite cases of primary pulmonary M. avium complex infection].

It is very difficult to treat pulmonary infection with MAC, because we have few effective drugs against this organism. In this situation, an early diagnosis and treatment are very important to manage this disease. We evaluated chest CT scans of the primary pulmonary MAC infection which had no underlying lung diseases and no immunocompromised diseases such as HIV infection. We defined suspected cases of pulmonary MAC infection as cases in which abnormal features of chest CT scans were recognized but frequency of detection of organisms of MAC did not fulfil the diagnostic criteria for atypical mycobacteriosis according to Japanese Mycobacteriosis Research Group of the National Chest Hospitals. CT scans of suspected cases were compared with the definite cases. Results obtained were as follows: 1. In classification by CT scans of primary pulmonary MAC infection, the proportion of localized type and diffuse type was the same both in suspected and definite cases. In localized type, more tuberculosis-like pattern was seen in definite cases. 2. In suspected cases, characteristic features of CT scans of primary pulmonary MAC infection were recognized in the same frequency as in definite cases. 3. In pulmonary tuberculosis-like type, definite cases showed more cavitary lesions than suspected cases. These results showed that a careful long term follow-up of suspected cases with frequent bacteriological tests of sputum and chest CT scannings was important for early diagnosis of primary pulmonary MAC infection.

Aged↗
PubMed2003

Evaluation of the WHO clinical case definition for pediatric HIV infection in Bloemfontein, South Africa.

The WHO clinical case definition for pediatric HIV infection has been designed to be used in countries where diagnostic laboratory resources are limited. We evaluated the WHO case definition to determine whether it is a useful instrument to discriminate between HIV-positive and HIV-negative children. In addition, clinical features not included in this case definition were recorded. We recorded clinical data from 300 consecutively admitted children in a state hospital in Bloemfontein, South Africa, and tested these children for HIV infection. A total of 222 children were included in the study; 69 children (31.1 per cent) were HIV positive. The sensitivity of the WHO case definition in this study was 14.5 per cent, the specificity was 98.6 per cent. Apart from weight loss and generalized dermatitis, the signs of the WHO case definition were significantly more often seen in HIV-positive than in HIV-negative children. Of the clinical signs not included in the WHO case definition, marasmus and hepatosplenomegaly especially occurred more frequently in HIV-positive children. Based on these findings we composed a new case definition consisting of four signs: marasmus, hepatosplenomegaly, oropharyngeal candidiasis, and generalized lymphadenopathy. HIV infection is suspected in a child presenting with at least two of these four signs. The sensitivity of this case definition was 63.2 per cent, the specificity was 96.0 per cent. We conclude that in this study the WHO case definition was not a useful instrument to discriminate between HIV-positive and HIV-negative children, mainly because its sensitivity was strikingly low. The simplified case definition we propose, proved to be more sensitive than the WHO case definition (63.2 vs. 14.5 per cent), whilst its specificity remained high.

AIDS-Related Opportunistic Infections↗
PubMed1989

Evaluation and simplification of the World Health Organization clinical case definition for paediatric AIDS.

The World Health Organization (WHO) clinical case definition for paediatric AIDS was tested during a 1-month period on 221 consecutive hospitalized children in Kigali, Rwanda. Relevant clinical features not included in the WHO case definition were also evaluated. Thirty-four out of the 221 children (15.4%) were HIV seropositive. Although the specificity of the WHO case definition was high (92%), the sensitivity and the positive predictive value (PPV) were low (41 and 48%, respectively). The following individual signs had a PPV at least equal to the complete WHO case definition: chronic diarrhoea (47%), respiratory distress secondary to lower respiratory tract infection (50%), oral candidiasis (53%), parotitis (67%), generalized lymphadenopathy (88%), and herpes zoster infection (100%). When logistic regression analysis was done on the nine variables included in the WHO case definition, confirmed maternal infection was the best predictive variable for HIV seropositivity in children (P less than 10(-5). We further excluded the serological status of the mother from the analysis and performed a stepwise logistic regression analysis on the 18 clinical signs and symptoms for which information had been collected. Those signs and symptoms contributing the most to the regression were: respiratory distress, chronic diarrhoea and generalized lymphadenopathy. Based on these findings, we propose a simplified clinical case definition for paediatric AIDS in Africa with better sensitivity, specificity and PPV than the WHO case definition. Further work is needed using this approach to develop case definitions useful for epidemiological surveillance and for case management.

Acquired Immunodeficiency Syndrome↗