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Distributed data entry and quality control
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Abstracts
Report and patient appointment schedules project future ideal visit dates. These reports assist study personnel in maintaining the orderly progression of patients and data.
The Diabetic Retinopathy Study Revisited William J. H u s t e r
The Johns Hopkins University, Baltimore, MD ($1) The Diabetic Retinopathy Study (DRS) was begun in 1971 to study the effectiveness of laser photocoagulation in treating diabetic retinopathy. One eye of each patient was randomly selected for treatment and the other eye observed without treatment. Previous analyses of this dataset have not taken into account the association between the eyes of the patient. Methods proposed by Clayton in 1978 to model this association are extended to allow censored data and covariates. The reanalysis confirms the efficacy of the treatment but on an even more significant scale than when the association is ignored. Also, an interesting interaction between the treatment and type of diabetes is detected. Thus, this paper provides a useful statistical technique for the analysis of naturally paired survival data.
Assessing Disease-Specific Quality of Life in Clinical Trials M. T o w n s e n d , G . H . G u y a t t , L.B. B e r m a n , a n d D.W. Taylor
Dept. Clinical Epidemiology & Biostatistics, McMaster University, Hamilton, Ontario, Canada ($2) Studies focusing on chronic disease can be hampered by lack of adequate measurement of quality of life (QOL). To develop a self-report QOL questionnaire for patients with chronic heart and lung disease, we asked 200 such patients how their quality of life was affected by their illness and the importance of their symptoms and limitations. The most frequent and important items were included in a questionnaire evaluating dyspnea, fatigue, and emotional function. Reproductibility was tested by administering the questionnaire six times over a 10-12 week interval to 43 stable patients. Responsiveness was demonstrated by administering the questionnaire to another group of 32 patients before and after participation in a respiratory rehabilitation program. Our new questionnaire is reproducible, valid, and responsive. Our strategy for questionnaire development and testing provides a model for constructing responsive disease-specific QOL measures for clinical trials.
Distributed Data Entry and Quality Control Mira Zalokar, Alfred Hallstrom, a n d Mary Jo Gillespie
University of Washington, Seattle, WA Distributed Data Entry (DDE) is being used more frequently in coordinated clinical trials. The principal arguments for DDE are timeliness and improved data quality. From the Coordinating Center for the Cardiac Arrhythmia Pilot Study, we report on our experience using DDE from the beginning of the study. We noted that the percentage of errors occurring at the sites in mid study was half that of the early stage. Also, upon detection of an error on the paper form, the sites more frequently than the Coordinating Center entered the correct value and then failed to update the paper form. The verification system we use is inadequate for our needs. It does not pick up logical discrepancies. We recommend that all forms be sent to the Coordinating Center for the first few months of the trial. This will enable one to discover and rectify any bugs in the programs. Also, a record of all changes done during verification would greatly expedite the quality control process.
Abstracts
Report and patient appointment schedules project future ideal visit dates. These reports assist study personnel in maintaining the orderly progression of patients and data.
The Diabetic Retinopathy Study Revisited William J. H u s t e r
The Johns Hopkins University, Baltimore, MD ($1) The Diabetic Retinopathy Study (DRS) was begun in 1971 to study the effectiveness of laser photocoagulation in treating diabetic retinopathy. One eye of each patient was randomly selected for treatment and the other eye observed without treatment. Previous analyses of this dataset have not taken into account the association between the eyes of the patient. Methods proposed by Clayton in 1978 to model this association are extended to allow censored data and covariates. The reanalysis confirms the efficacy of the treatment but on an even more significant scale than when the association is ignored. Also, an interesting interaction between the treatment and type of diabetes is detected. Thus, this paper provides a useful statistical technique for the analysis of naturally paired survival data.
Assessing Disease-Specific Quality of Life in Clinical Trials M. T o w n s e n d , G . H . G u y a t t , L.B. B e r m a n , a n d D.W. Taylor
Dept. Clinical Epidemiology & Biostatistics, McMaster University, Hamilton, Ontario, Canada ($2) Studies focusing on chronic disease can be hampered by lack of adequate measurement of quality of life (QOL). To develop a self-report QOL questionnaire for patients with chronic heart and lung disease, we asked 200 such patients how their quality of life was affected by their illness and the importance of their symptoms and limitations. The most frequent and important items were included in a questionnaire evaluating dyspnea, fatigue, and emotional function. Reproductibility was tested by administering the questionnaire six times over a 10-12 week interval to 43 stable patients. Responsiveness was demonstrated by administering the questionnaire to another group of 32 patients before and after participation in a respiratory rehabilitation program. Our new questionnaire is reproducible, valid, and responsive. Our strategy for questionnaire development and testing provides a model for constructing responsive disease-specific QOL measures for clinical trials.
Distributed Data Entry and Quality Control Mira Zalokar, Alfred Hallstrom, a n d Mary Jo Gillespie
University of Washington, Seattle, WA Distributed Data Entry (DDE) is being used more frequently in coordinated clinical trials. The principal arguments for DDE are timeliness and improved data quality. From the Coordinating Center for the Cardiac Arrhythmia Pilot Study, we report on our experience using DDE from the beginning of the study. We noted that the percentage of errors occurring at the sites in mid study was half that of the early stage. Also, upon detection of an error on the paper form, the sites more frequently than the Coordinating Center entered the correct value and then failed to update the paper form. The verification system we use is inadequate for our needs. It does not pick up logical discrepancies. We recommend that all forms be sent to the Coordinating Center for the first few months of the trial. This will enable one to discover and rectify any bugs in the programs. Also, a record of all changes done during verification would greatly expedite the quality control process.