Method Of Case Identification Research Articles

Identification of fractures from computerized medicare files

Study of non-hip fractures, which are a serious public health problem for persons ⩾ 65 years of age, has been hindered by the absence of an economical method for case identification. We assessed the utility of computerized Medicare inpatient, emergency room, hospital outpatient department and physician claims for identifying fractures in an elderly Tennessee Medicaid population. We used these files for 1987 to identify 3086 possible fractures and reviewed medical records for a sample of 1440. Using this sample, we developed a definition of probable fractures that excluded claims unlikely to represent newly diagnosed fractures. For all fractures, this definition had a positive predictive value of 94%, which for individual fracture sites, ranged from 79% (tibia/fibula) to 98% (hip). Of fractures in the reviewed sample, 91% were identifed as probable fractures; this upper bound for sensitivity varied between 75% (femoral shaft) and 100% (patella). These data suggest that computerized Medicare files can be used for rapid and economical fracture ascertainment among persons ⩾ 65 years of age. However, further work is needed to obtain better estimates of sensitivity.

Birth and population prevalence of Duchenne muscular dystrophy in the Netherlands

Mutations causing Duchenne muscular dystrophy (DMD) have a short survival. Therefore, birth and population prevalence are maintained by new mutations. The present inventory was made to estimate the birth and population prevalence rates of DMD in the Netherlands. Seven methods of case identification were used. Data on 496 definite, probable or possible DMD patients born since 1961, or alive on January 1, 1983, were obtained. Several methods gave an estimated ascertainment of more than 95%. The prevalence rate at birth of DMD was estimated at 23.7 x 10(-5) (1:4215) male live births (MLB) yearly. The prevalence rate in the male population on January 1, 1983 was 5.4 x 10(-5) (1:18496). About 1% of the males in this study may have autosomal recessive Duchenne-like muscular dystrophy. Until now there has been no convincing evidence for geographic differences in DMD prevalence at birth. A list of frequency studies of Duchenne muscular dystrophy is included. The DMD mutation rate calculated by the indirect method is 7.9 x 10(-5) genes per generation. However, this may well be an over-estimate, as this method does not account for germline mosaicism. Using a modified sex ratio method the proportion of sporadic DMD among all cases was estimated to be 0.106 (range 0-0.332). High frequency of germline mosaicism in DMD is a likely cause for the apparent lack of sporadic cases as found in previous studies, if mutation rates in male and female gametes are equal. Therefore, methods for estimating the proportion of new mutants in DMD should take germline mosaicism into account. The modified sex ratio method allows incorporation of data on germline mosaicism if available.

Identification of Cases of Myocardial Infarction: Hospital Discharge Data and Mortality Data Compared to Myocardial Infarction Community Registers

Identification of incident myocardial infarction (MI) cases in a defined population using hospital discharge data and mortality data in combination has been suggested. This method of case identification was compared to that of use of MI community registers set up in accordance with principles adopted in a World Health Organization collaborative programme. The comparison comprised data for four Swedish cities over a number of years. On average 81% of incident hospital-treated cases below 65 years of age identified through MI community registers were found by the retrospective use of the method based on hospital discharge data and mortality data. Of hospital-treated cases identified by the latter method, 83% were also found by the MI community registers. For cases fulfilling the diagnostic criteria employed by the MI community registers this proportion would be higher, probably 87%-92%. Several reasons for cases being missed by either method were suggested by the results. According to the findings of this study, the case identification of the method based on hospital discharge data and mortality data seems to be somewhat less efficient compared to use of MI community registers. This may be of importance in descriptive epidemiological studies, but is of less significance in analytical studies. The relative efficiency of the former method could be improved by a more reliable system for the recording of hospital discharges. If supplemented by a validation procedure, it could yield sufficiently accurate data for many epidemiological applications at a fairly low cost.

Mental illness in a cross-national perspective

Findings for unselected samples for the elderly in two urban populations - one in Mannheim, Germany (n = 418) and the other in Sao Paulo, Brazil (n = 111) - are compared and contrasted. Each study was restricted to persons aged over 65 years living in private households, and each employed a single-stage method of psychiatric case-identification, based on the Clinical Interview Schedule (CIS). Apart from marked differences in educational standards and proportions living alone the two samples were broadly similar in their recorded socio-demographic characteristics. Comparison revealed no significant difference in total prevalence, though there was a trend towards a higher case-frequency in Sao Paulo (29.7%) than in Mannheim (23.3%). The clinical-item profiles for the two samples indicated a higher rate of symptom reporting in Sao Paulo, whereas the Mannheim sample had higher mean scores for a number of psychiatric abnormalities observed at interview. Separate cluster analyses carried out on the two data sets divided the samples into four pairs of sub-groups with similar clinical profiles, which were designated respectively as 'organic', 'depressive', 'neurotic' and 'normal'. While a more careful standardization of method would probably reduce the observed disparities between the samples, some of these are thought to be real and to relate to sociocultural differences, as well as to the greater stresses of daily life in Sao Paulo.

The case identification of dementia in the community: A comparison of methods

AbstractFew studies have compared methods of case identification in dementia in detail. In this epidemiological study of cognitive function and dementia, scales and clinical diagnoses were compared in 365 women aged between 70 and 79. The women were interviewed using CAMDEX (Cambridge Examination for Mental Disorders of the Elderly), which includes established and new scales of cognitive function and behaviour. In addition, the information/orientation subscale of the Clifton Assessment Procedure for the Elderly was recorded. The proportions of the population identified by various recommended cutpoints for these scales were calculated. Sensitivities and specificities for these were compared, using CAMDEX clinical diagnosis as the standard. Large differences were found in these according to both the cutpoint set and the level of dementia examined. Each subject was rated by her own general practitioner and a random 10% of the sample was seen using the Geriatric Mental State Examination in addition to CAMDEX. The different diagnoses were compared and considerable variation found.

Lifetime prevalence of cognitive impairment by Chinese-modified NIMH diagnostic interview schedule among the elderly in Taiwan communities

Lifetime prevalence of cognitive impairment by Chinese-Modified NIMH Diagnostic Interview Schedule (DIS-CM) among the community population aged 65 and over in Taipei City, 2 townships and rural villages, are: 2.8%, 12.9% and 12.9% for definitely mild ; 1.6%, 9.0% and 5.4% for definitely mild and possibly severe; and 1.3%, 9.6% and 1.8% for definitely severe cases, respectively. The prevalences increase with age in both sexes. In general, prevalence rates are higher in females than males with some inconsistent differences between severity of impairment and age-groups in each of three sites. High rates of errors in and/or refusal of three specific questions in both cases and noncases are noteworthy. Whether this indicates the limitations of the DIS-CM in case-identification of cognitive impairment in the elderly in Chinese community population deserves further study. The lower rate of severe cognitive impairment among the elderly in urban than that in rural areas as indicated in this study is in accord with the NIMH ECA Studies which adopted the similar case-finding method, and also with two recent studies in Taiwan which used the different case-identification method.

Identifying anxiety and depressive disorders among primary care patients: a pilot study.

One stage case-identification method, using the Arabic Version of the Hospital Anxiety and Depression Scale (HAD) was applied in a pilot study for estimating the prevalence of depressive and anxiety disorders among a group of Saudi primary care attenders. The validity of the Arabic Version of the HAD scale was previously tested and found valid with high sensitivity and specificity. The total prevalence rate of depression was 17% and that of anxiety was 16%. Seven percent of the sample suffered both depression and anxiety i.e. the total percentage of patients with depression, anxiety or both was 26%. Higher morbidity of depression was recorded among females and a higher morbidity of anxiety among male patients.

A pilot study of mental disorders in Taiwan.

A two-stage case-identification method, using a modified General Health Questionnaire (GHQ) and the Clinical Interview Schedule (CIS), was applied in a pilot study of mental disorders in an urban city in Taiwan. The validity of the modified GHQ was proved to be greater than that of the original, with a very high sensitivity and specificity. The Chinese version of the CIS was found to be feasible for community study in Taiwan. The total prevalence rate of all mental disorders was 26.0%, with a higher morbidity among females.

Psychiatric case detection in gynaecological patients.

There is a large and conflicting literature on the frequency and nature of psychiatric disorders in women with gynaecological conditions. It is difficult to interpret and compare the findings of different studies, largely because they have used non-standardised methods of case-identification. The aim of this paper is to illustrate the use of standardised methods of case detection in two gynaecological populations: women undergoing hysterectomy and those receiving elective tubal sterilisation. Three applications of case-identification techniques are described: measuring prevalence; describing features of the disorders; and testing hypotheses. Examples of each are given for the two gynaecological populations.

Determinants of the ability of general practitioners to detect psychiatric illness.

This study of psychiatric illness among 4098 patients attending 91 general practitioners compares 2 methods of case identification: 'conspicuous morbidity' by the doctor's own assessments, and 'probable prevalence' by the patients' responses to the General Health Questionnaire (GHQ). In general, the latter gives somewhat higher estimates than the former, but there are wide variations in morbidity between practices. The ability of each general practitioner to detect psychiatric illness was measured by computing Spearman's correlation coefficient between his assessments and the GHQ scores of his patients. The mean correlation coefficient was + 0.36, but the range was very wide (0.09-0.60). The first part of the study deals with various demographic characteristics of the patients themselves which are associated with an increased likelihood of the doctor detecting a psychiatric illness; such factors include unemployment, female sex, and marriages which have ended by separation, divorce or death. The second part of the study examines characteristics of the doctors themselves in an attempt to account for the wide variation between them in their ability to detect psychiatric illness. A research psychiatrist made detailed observations on 2098 interviews carried out by 55 general practitioners. Each doctor's verbal and non-verbal styles were recorded minutely, and in addition various global ratings were made. The doctors completed personality inventories and supplied details of training and professional background. It was possible to account for 67% of the variance of correlation coefficient mainly in terms of 2 dimensions: 'interest and concern' and 'conservatism'. The way in which the doctor interviews his patients is shown to be important, but there are interactions between interview style and the doctor's personality.

Psychiatric Disorders in Two African Villages

Adults in two small Ugandan villages were interviewed, using a standard psychiatric examination and standard methods of case identification and diagnosis. Twenty percent had disorders just above threshold level, and a further 5% had more definite disorders. Most of these conditions were depressive, but hypomanic and anxiety states were also represented. A survey of women in southeast London found only half this frequency of disorders. Further studies are required to confirm these results.

EMOTIONAL DISORDERS IN SIX ISRAELI VILLAGES

This is a report on a psychiatric epidemiological census conducted in six Israeli villages. The method of case identification relied on data extracted from medical cards and the use of two shortened versions of the CMI. The results showed a distribution affected by sex, age, ethnicity, education, and "status consumer". A comparison with other Israeli studies is made.

Psychiatric Illness in General Practice: A Detailed Study Using a New Method of Case Identification

A self-administered questionary (the General Health Questionnaire) aimed at detecting current psychiatric disturbance was given to 553 consecutive attenders to a general practitioner's surgery. A sample of 200 of these patients was given an independent assessment of their mental state by a psychiatrist using a standardized psychiatric interview. Over 90% of the patients were correctly classified as "well" or "ill" by the questionary, and the correlation between questionary score and the clinical assessment of severity of disturbance was found to be +0.80.The "conspicuous psychiatric morbidity" of a suburban general practice assessed by a general practitioner who was himself a psychiatrist and validated against independent psychiatric assessment was found to be 20%. "Hidden psychiatric morbidity" was found to account for one-third of all disturbed patients. These patients were similar to patients with "conspicuous illnesses" in terms both of degree of disturbance and the course of their illnesses at six-month follow-up, but were distinguished by their attitude to their illness and by usually presenting a physical symptom to the general practitioner.When 87 patients who had been assessed as psychiatric cases at the index consultation were called back for follow-up six months later, two-thirds of them were functioning in the normal range. Frequency of attendance at the surgery in the six months following index consultation was found to have only a modest relationship to severity of psychiatric disturbance.It is argued that minor affective illnesses and physical complaints often accompany each other and usually have a good prognosis.

A standardized psychiatric interview for use in community surveys.

Surveys of psychiatric illness in the community are at present handicapped by the lack of valid and reliable methods of case-identification. The widely varying estimates of psychiatric prevalence made by different workers in this field (Lin and Standley, 1962) emphasize the urgent need for such tech niques, which could be used both in field surveys and in the screening of general practice populations. In large-scale psychiatric surveys, the use of a two-stage screening procedure is desirable and may, indeed, be essential for economic reasons. The first stage entails the selection of possible or 'potential' cases by means of a rapid and simply administered screening test; the second comprises detailed clinical examination of such potential cases in order that they may be confirmed as actual cases (Blum, 1962) and given an accurate diagnostic assessment. The present paper is concerned only with the second of these stages, namely, the development of a standard ized psychiatric interview and rating technique suitable for application to potential cases in a com munity setting. A number of standardized psychiatric interviews, including some which are highly reliable, have been developed in recent years, but for various reasons all are unsuitable for field surveys. In the United States, Lorr, Klett, and McNair (1963) have de scribed an assessment based on the Inpatient Multi dimensional Psychiatric Scale (IMPS), and Overall and Gorham (1962) have used a psychiatric assess ment derived from a shortened version of the Lorr scale; both these scales heavily emphasize psychotic phenomena which are relatively uncommon in the general population. The interview described by Spitzer, Fleiss, Burdock, and Hardesty (1964), although in some ways more suitable, is still in sufficiently flexible and contains many items which would make it unacceptable to normal individuals. In this country, Wing, Birley, Cooper, Graham, and Isaacs (1967) and Kendell, Everitt, Cooper, Sar torius, and David (1968) have published accounts of the 'Present State Examination' which has been designed primarily for use in international studies. This very comprehensive 500-item schedule was designed for administration to known psychiatric patients and again does not readily lend itself in its present form for use in community surveys. With these considerations in mind, a standardized psychiatric interview has been constructed to meet the following requirements: (1) Psychiatric assessment should be made by an experienced psychiatrist in a realistic ciinical setting; (2) The interview should be acceptable to indi viduals who may not see themselves as psychiatrically disturbed; (3) The content of the interview should be appro priate to the types of psychiatric disturbance com monly encountered in the community; (4) The interview should generate information about individual symptoms and signs of illness as well as an overall diagnostic assessment;