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A comparison of functional status measures in chronic lung disease: Data from a randomized control trial
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Abstracts
unaware of treatment and do not have access to previous Doppler examinations). Inter- and intrarater variation and diagnosis suspicion bias were minimized by establishing a standardized interpretation scale. Continued blindedness assures reliability and minimizes other potential study biases.
A Comparison of Functional Status Measures in Chronic Lung Disease: Data from
a Randomized Control Trial J.L. Keller, G . H . G u y a t t , M. T o w n s e n d , a n d D. S h o r t
Department of Medicine and Clinical Epidemiology and Biostatistics, McMaster University, Hamilton, Ontario (18) Although a n u m b e r of instruments for measurement of functional status in randomized trials
are available, they have never been compared in the setting of a randomized control trial. We therefore compared the responsiveness and validity of the Chronic Respiratory Disease Questionnaire (CRQ), the Oxygen Cost Diagram (OCD), and the Medical Research Council dyspnea questionnaire as modified by investigators from the Rand Corporation (Rand Instrument) in a double-blind, randomized crossover trial in which 19 patients with primarily fixed chronic airflow limitation received placebo, inhaled salbutamol, oral theophylline, and both active drugs, each for 2 weeks. Statistically significant salbutamol and theophylline effects were detected by the CRQ, but not by the OCD or Rand questionnaire. Because there is no gold standard for measuring functional status in chronic airflow limitation, validity was assessed through examining correlations between changes in score on the three questionnaires and changes in spirometry, walk test score, and global ratings of physical function. Correlations were highest using the CRQ, lower for the OCD, and lowest for the Rand Instrument. These results indicate that the CRQ, the OCD, and the Rand instrument rank first, second, and third, respectively, in terms of both responsiveness and validity. The experiment illustrates the feasibility, usefulness, and importance of direct comparisons of functional status and quality of life measures in the clinical trial setting.
Using an Expert System to Automate the Element of Clinical Judgment in Data Analyses J.M. L o n g , J.F. Slagle, M. Wick, J.P. M a t t s , A.R. L e o n , a n d t h e P O S C H ECG P a n e l University of Minnesota (19) Expert systems provide a way to automate processes where clinical judgment is a factor. Their use has been demonstrated in diagnosing and as a consultant. We attempted to use expert systems technology in a new way, namely to automate the serial assessment of clinical data where clinical judgment is a necessary part; for example, serial arteriography and stress test data. The concept was tested using a set of 100 pairs of POSCH serial ECG stress tests assessed on a seven-point scale. The POSCH ECG Panel (PR) review was used as the standard. The expert system (ES) and a statistically based model (SM), developed on a separate set of data, were then compared with the results of the panel. Exact agreement was poor for all approaches. Kappa statistics were: ES vs PR = 0.21, SM vs PR = 0.19. Agreement within one category was better. ES vs PR = 0.75, SM vs PR = 0.74. These results approximate individual cardiologists (IC) with themselves: IC vs PR = 0.24 and 0.78. We conclude that expert systems are a viable way to automate the assessment of research data where clinical judgment is an important factor.
Use of a Relational Data Base Management System J a n e t Reis a n d Patricia B u r n s
State University of New York at Buffalo, Buffalo, New York (20) This paper summarizes the development, implementation, and use of a relational data base system for a controlled clinical trial of behavioral treatments for female urinary stress incontinence. The R Base 4000 software package was used to create 52 customized screens for forms entry of over 7000 variables for an anticipated 120 study participants. Approximately 2 months were required to create the data system. Average entry time for all forms is 500 minutes.
Abstracts
unaware of treatment and do not have access to previous Doppler examinations). Inter- and intrarater variation and diagnosis suspicion bias were minimized by establishing a standardized interpretation scale. Continued blindedness assures reliability and minimizes other potential study biases.
A Comparison of Functional Status Measures in Chronic Lung Disease: Data from
a Randomized Control Trial J.L. Keller, G . H . G u y a t t , M. T o w n s e n d , a n d D. S h o r t
Department of Medicine and Clinical Epidemiology and Biostatistics, McMaster University, Hamilton, Ontario (18) Although a n u m b e r of instruments for measurement of functional status in randomized trials
are available, they have never been compared in the setting of a randomized control trial. We therefore compared the responsiveness and validity of the Chronic Respiratory Disease Questionnaire (CRQ), the Oxygen Cost Diagram (OCD), and the Medical Research Council dyspnea questionnaire as modified by investigators from the Rand Corporation (Rand Instrument) in a double-blind, randomized crossover trial in which 19 patients with primarily fixed chronic airflow limitation received placebo, inhaled salbutamol, oral theophylline, and both active drugs, each for 2 weeks. Statistically significant salbutamol and theophylline effects were detected by the CRQ, but not by the OCD or Rand questionnaire. Because there is no gold standard for measuring functional status in chronic airflow limitation, validity was assessed through examining correlations between changes in score on the three questionnaires and changes in spirometry, walk test score, and global ratings of physical function. Correlations were highest using the CRQ, lower for the OCD, and lowest for the Rand Instrument. These results indicate that the CRQ, the OCD, and the Rand instrument rank first, second, and third, respectively, in terms of both responsiveness and validity. The experiment illustrates the feasibility, usefulness, and importance of direct comparisons of functional status and quality of life measures in the clinical trial setting.
Using an Expert System to Automate the Element of Clinical Judgment in Data Analyses J.M. L o n g , J.F. Slagle, M. Wick, J.P. M a t t s , A.R. L e o n , a n d t h e P O S C H ECG P a n e l University of Minnesota (19) Expert systems provide a way to automate processes where clinical judgment is a factor. Their use has been demonstrated in diagnosing and as a consultant. We attempted to use expert systems technology in a new way, namely to automate the serial assessment of clinical data where clinical judgment is a necessary part; for example, serial arteriography and stress test data. The concept was tested using a set of 100 pairs of POSCH serial ECG stress tests assessed on a seven-point scale. The POSCH ECG Panel (PR) review was used as the standard. The expert system (ES) and a statistically based model (SM), developed on a separate set of data, were then compared with the results of the panel. Exact agreement was poor for all approaches. Kappa statistics were: ES vs PR = 0.21, SM vs PR = 0.19. Agreement within one category was better. ES vs PR = 0.75, SM vs PR = 0.74. These results approximate individual cardiologists (IC) with themselves: IC vs PR = 0.24 and 0.78. We conclude that expert systems are a viable way to automate the assessment of research data where clinical judgment is an important factor.
Use of a Relational Data Base Management System J a n e t Reis a n d Patricia B u r n s
State University of New York at Buffalo, Buffalo, New York (20) This paper summarizes the development, implementation, and use of a relational data base system for a controlled clinical trial of behavioral treatments for female urinary stress incontinence. The R Base 4000 software package was used to create 52 customized screens for forms entry of over 7000 variables for an anticipated 120 study participants. Approximately 2 months were required to create the data system. Average entry time for all forms is 500 minutes.