A quality study of a medical birth registry

A quality control study was made of the Swedish Medical Birth Registry. This registry used one mode of data collection during 1973-1981 and another from 1982 onwards. The number of errors in the register was checked by comparing register information with a sample of the original medical records, and the variability in the use of diagnoses between hospitals was studied. Different types of errors were identified and quantified and the efficiency of the two methods of data collection evaluated.

Evaluation of a new method for verifying truth of diagnosis in clinical research

Having a good methodology for establishing truth of diagnosis would be invaluable to researchers in radiology. A protocol to verify the truth of diagnosis of clinical images to be used in radiologic research has been proposed that specifies six classes, depending on how the diagnosis is verified. In this paper it was evaluated. The protocol was applied to sixty-nine liver-spleen scans. Using five of the possible six classes of the protocol, 42% of the scans were verifiable. Twenty-eight per cent of the cases could be verified by non-physicians using the first four classes of the protocol. In 96% of a sample of these cases, their diagnosis matched that of the physicians. Radiologists are needed for the last two classes. However, using three radiologists to investigate Class V protocol procedures only eight (16%) more cases were clearly classifiable. Class VI was not investigated. The protocol met its objectives of reducing physician involvement and developing a detailed methodology. The difficulties inherent in verification of diagnosis are also discussed, and suggestions for improving the protocol are proposed.

Latent class analysis of diagnostic agreement

We describe methods based on latent class analysis for analysis and interpretation of agreement on dichotomous diagnostic ratings. This approach formulates agreement in terms of parameters directly related to diagnostic accuracy and leads to many practical applications, such as estimation of the accuracy of individual ratings and the extent to which accuracy may improve with multiple opinions. We describe refinements in the estimation of parameters for varying panel designs, and apply latent class methods successfully to examples of medical agreement data that include data previously found to be poorly fitted by two-class models. Latent class techniques provide a powerful and flexible set of tools to analyse diagnostic agreement and one should consider them routinely in the analysis of such data.

Hospital discharge diagnoses: how accurate are they and their international classification of diseases (ICD) codes?

The accuracy of the discharge diagnoses recorded in hospital medical records, and the accuracy of their ICD codes, were retrospectively examined in 174 randomly chosen hospital patients. There was a 29% error rate in the recorded ICD codes when compared at a three digit level to the results obtained by retrospectively reviewing the records, establishing diagnoses and coding them. The error rate increased when medical records coders, rather than medically trained personnel, undertook the task of establishing the discharge diagnoses.

Statistical methods for assessing agreement between two methods of clinical measurement

In clinical measurement comparison of a new measurement technique with an established one is often needed to see whether they agree sufficiently for the new to replace the old. Such investigations are often analysed inappropriately, notably by using correlation coefficients. The use of correlation is misleading. An alternative approach, based on graphical techniques and simple calculations, is described, together with the relation between this analysis and the assessment of repeatability.

Community hospital management of pediatric emergencies: implications for pediatric emergency medical services

The ability of emergency physicians in a general community hospital to manage pediatric patients was evaluated. Essential diagnostic and therapeutic procedures performed in the emergency department on pediatric patients transferred for admission to a tertiary care center were compared with those initially performed on the same patients by the pediatricians and residents of the tertiary care center. The overall care rendered by the emergency physicians correlated well with that of the referral center. Ninety one per cent of diagnostic studies and 96% of therapeutic interventions were performed in the emergency department. Implications for the care of seriously ill pediatric patients by emergency physicians and the role of community hospital emergency departments in pediatric emergency medical services (EMS) systems are discussed.

The assessment of diagnostic tests. A survey of current medical research

To study current diagnostic test evaluation, 129 recent articles were assessed against several well-known methodological criteria. Only 68% employed a well-defined "gold standard." Test interpretation was clearly described in only 68% and was stated to be "blind" in only 40%. Approximately 20% used the terms sensitivity and specificity incorrectly. Predictive values were considered in only 31% and the influence of disease prevalence and study setting was considered in only 19%. Overall, 74% failed to demonstrate more than four of seven important characteristics and there was an increased proportion of high specificities reported in this group. Articles assessing new tests reported high sensitivities and specificities significantly more often than articles assessing existing tests. These results indicate a clear need for greater attention to accepted methodological standards on the part of researchers, reviewers, and editors.

Receiver operating characteristic analysis of diagnostic skill

In an effort to assess diagnostic skill, the authors collected estimates of the probability of positive results for 392 chest x-rays and 595 throat cultures from 56 pediatricians at different stages in training. Positivity rates were 28.6% for x-rays and 32.9% for throat cultures. The ability to predict the outcome of chest x-rays (pneumonia or not) improved with training on two measures: 1) "calibration," the accuracy of the guessed probability of positivity, and 2) "operating characteristic," the ability to sort patients with negative x-rays from patients with positive x-rays. Improvement was most marked in the ability to predict that a patient with a positive x-ray would have a positive x-ray. For throat culture results, no regular improvement was found with training either in calibration or in operating characteristic. Measurements of calibration and operating characteristic are useful for assessing the effect of training on diagnostic skill.

Quality assurance of clinical data: diagnostic standardization

Diagnostic standardization requires substantial effort, including detailed specification of procedures in a written protocol and training of examiners in such procedures. Success is neither automatic nor assured. It is essential to monitor performance through replicate examinations and/or computation of examiner variance. When examiner variance exceeds permissible limits, consideration should be given to discarding the data.

Is there duplication of diagnostic test results?

Images

Temporal orientation in patients with brain disease

A brief schedule of questions, based on empirically derived norms, disclosed significant inaccuracy in temporal orientation in 24% of a groups of nonaphasic patients with brain disease. Conventional neurological examination detected temporal disorientation in only 15%. Patients with bilateral lesions showed a higher frequency of temporal disorientation than did those with inilateral lesions. In a group of 15 aphasic patients, 5 (33%) showed evidence of temporal disorientation according to the test while only 3 (20%) were detected on clinical examination. It is suggested that a schedule of questions scored on the basis of empirically derived norms should be incorporated into the neurological examination to assess temporal orientation.