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Variability of CD4 counts, a surrogate marker for disease progression in HIV-infected individuals
Absffads
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rationale and the corresponding analyses are also presented in this paper. Two specific examples are given: one for an anti-hypertensive drug; the other is for cateoarthritis.
A13 VARIABILITY OF CD4 COUNTS, A SURROGATE ILARKER FOR DISEASE PROGRESSION IN HIV-INFECTED INDIVIDUALS Victor Abel, Sarah Gill, ICmen Gelmon and the Conoorde Immunology Working Group and I n v e ~
MRC HIV Clinical Trials C,en~e Royal Brompton Hospital London, England Progressive reduction in the numbers of T-helper lymphocytes (CD4 cells) is the hallmark of immunodeficiency associated with human immunodeticlancy virus (HIV) infection. Recently recommendations have been made to treat with zidovudine esymptomatio subjects who have CD4 counts of less than 200, or between 200 and 500 celis/mms and "rapidly falling." However, there is little published on the reliability of the CD4 count. In this paper we report on: i) a 95% reference range for e sample of 50 seronogative homosexual men of between 424 (95% CI 364 to 493) and 1,451 (95% CI 1,247 to 1,689) cells/mms ii) within subject variation at weeks -4 and 0 in the intake to the MRC/INSERM Concorde Triai iii) laboratory variation in e set of quality control exercises using centers participating in the Concorde triai. The results of these exercises will be discussed in the light of the treatment recommendations for asymptomatic HIV infected individuals.
A14 OUTCOME MEASURES IN A CUNICAL TRIAL TO COMPARE TWO METHODS OF MANAGEMENT OF TIBIAL FRACTURES GIIIlan M. R i b
University of Edinburgh Edinburgh, Scotland Long bone fractures are now often managed by fixation with a mechanical device, rather than by immobilization with plaster of pads. Different centers have developed their own devices and associated manegement procedures. These treatments have seldom been evaluated in controlled triais. This paper will present results from a randomized clinical triai of intemai versus extemai fixation for tibiai fractures. Particular interest focuses on the choice of outcome measure. The most commonly used measure in orthopedics is "time to clinical union." However, this is an unreliable measure, and may be spuriousiy influenced by the fixation procedure. An altemative outcome in the form of a patient questionnaire about functional movement will be descdbed, and correlated with the =time to union" data. The score derived from this questionnaire can be weighted by the patient's estimate of their need to perform certain tasks.
AIS CHOICE OF A RADIOLOGICAL END-POINT IN THE EVALUATION OF THE EFFECT OF DRUGS ON ATHEROSCLEROTIC LESIONS OR RESTENOSIS AFTER ANGI'OPLASTY M. Llevre end J.P. Bolseel
Unitd de Pharmecologie Clinique Lyon, France The demonstration of an effect on artery well lesions is an important step in the development of drugs aimed at treating atherosclerosis. In spite of its shortcomings, angiography is still the golden standard for the study of artedai lesions, and the only available technique for coronary arteries. Since the choice of a main and-point is pivotal in the design of a clinical triai, we have investigated the possible choices of a rediologic and-point in trials evaluating the effects of drugs on atherosclerotic lesions or restenosls after engioplasty. Binary end-points such as progression of atherosclerosis or restenosis after angioplesty have been used
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rationale and the corresponding analyses are also presented in this paper. Two specific examples are given: one for an anti-hypertensive drug; the other is for cateoarthritis.
A13 VARIABILITY OF CD4 COUNTS, A SURROGATE ILARKER FOR DISEASE PROGRESSION IN HIV-INFECTED INDIVIDUALS Victor Abel, Sarah Gill, ICmen Gelmon and the Conoorde Immunology Working Group and I n v e ~
MRC HIV Clinical Trials C,en~e Royal Brompton Hospital London, England Progressive reduction in the numbers of T-helper lymphocytes (CD4 cells) is the hallmark of immunodeficiency associated with human immunodeticlancy virus (HIV) infection. Recently recommendations have been made to treat with zidovudine esymptomatio subjects who have CD4 counts of less than 200, or between 200 and 500 celis/mms and "rapidly falling." However, there is little published on the reliability of the CD4 count. In this paper we report on: i) a 95% reference range for e sample of 50 seronogative homosexual men of between 424 (95% CI 364 to 493) and 1,451 (95% CI 1,247 to 1,689) cells/mms ii) within subject variation at weeks -4 and 0 in the intake to the MRC/INSERM Concorde Triai iii) laboratory variation in e set of quality control exercises using centers participating in the Concorde triai. The results of these exercises will be discussed in the light of the treatment recommendations for asymptomatic HIV infected individuals.
A14 OUTCOME MEASURES IN A CUNICAL TRIAL TO COMPARE TWO METHODS OF MANAGEMENT OF TIBIAL FRACTURES GIIIlan M. R i b
University of Edinburgh Edinburgh, Scotland Long bone fractures are now often managed by fixation with a mechanical device, rather than by immobilization with plaster of pads. Different centers have developed their own devices and associated manegement procedures. These treatments have seldom been evaluated in controlled triais. This paper will present results from a randomized clinical triai of intemai versus extemai fixation for tibiai fractures. Particular interest focuses on the choice of outcome measure. The most commonly used measure in orthopedics is "time to clinical union." However, this is an unreliable measure, and may be spuriousiy influenced by the fixation procedure. An altemative outcome in the form of a patient questionnaire about functional movement will be descdbed, and correlated with the =time to union" data. The score derived from this questionnaire can be weighted by the patient's estimate of their need to perform certain tasks.
AIS CHOICE OF A RADIOLOGICAL END-POINT IN THE EVALUATION OF THE EFFECT OF DRUGS ON ATHEROSCLEROTIC LESIONS OR RESTENOSIS AFTER ANGI'OPLASTY M. Llevre end J.P. Bolseel
Unitd de Pharmecologie Clinique Lyon, France The demonstration of an effect on artery well lesions is an important step in the development of drugs aimed at treating atherosclerosis. In spite of its shortcomings, angiography is still the golden standard for the study of artedai lesions, and the only available technique for coronary arteries. Since the choice of a main and-point is pivotal in the design of a clinical triai, we have investigated the possible choices of a rediologic and-point in trials evaluating the effects of drugs on atherosclerotic lesions or restenosls after engioplasty. Binary end-points such as progression of atherosclerosis or restenosis after angioplesty have been used