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P122 QUALITY CONTROL IN THE DIABETES CONTROL AND COMPLICATIONS TRIAL (DCCT)

Walter Owen, Patrlcle Cleary, F. John Service and Rodney Lorenz The George Washington University Biostatis~cs Center

Rockville, Maryland

The DCCT is a controlled clinical tdal designed to study the effects of intensive insulin therapy on diabetes complications. Samples collected at 29 centers in the U.S. and Canada are analyzed by a central biochemistry laboratory (CBL), an ophthalmologic reading unit, ECG and neurology reading units and nutritional and neurobehavioral coding units. Study personnel are trained and certified in the collection of data.

Data quality is assured by a multicomponent system: (1) data are double keyed; (2) edit messages are mailed monthly; (3) precision of central unit measurements is monitored by an external quality surveillance system. For example, masked split duplicates of 10% of all laboratory specimens are analyzed by the CBL to assess the entire process of collection, analysis and reporting of biochemical data. The hemoglobin AIc data is critical to the DCCT, therefore special measures are used to monitor precision over time. Annual rereadings of fundus photographs check for potential drift in the grading system. Comparable mechanisms of QC have been initiated at the other units.

The results of QC monitoring systems are reviewed by internal study committees. Although minor irreg- ularities have been detected by the system, such as a correctable problem in patient collected home blood profilsets, overall performance has been excellent.

P123 DEVELOPING A QUALITY CONTROL (QC) PROGRAM FOR BONE DENSITY MEASUREMENTS

IN A MULTICENTER TRIAL: THE POSTMENOPAUSAL ESTROGEN/PROGESTIN INTERVENTIONS (PEPI) EXPERIENCE

Carol H. Wasllauskas and H. Bradley Wells Bowman Gray School of Medicine

Winston-Salem, North Carolina

Bone density measurements have become an increasingly important end-point in many clinical trials. On- site, rather than central, measurements present several challenges for QC in the collection and processing of scans. The PEPI Tdal requires bone density measurements of lumbar spine and hip at Baseline, 12 and 36 months on women at 7 clinical centers. To control for variation inherent in measurements done with different instruments and operators, at different sites and over time, the PEPI Coordinating Center has implemented a QC program which includes:

• Central Purchase of Equipment • Special Training of Instrument Operators • A Manual of Procedures for PEPI Bone Scans • Repeated (Duplicate) Hip and Spine Scans • Special Data Forms • A Bone Scan Quality Control Center to:

Review scans and calibration data Reenalyze and correct scans Circulate a =Gold Standard" Phantom Provide technical assistance to clinics

This presentation reviews the development and implementation of the various aspects of the QC program. Preliminary QC data indicate that the coefficient of variation in the error of measurement, based on repeated scans, is 1.6% for the spine and 1.7% for the hip scans.

P124 GUIDELINES FOR MONITORING COMPANY SPONSORED CLINICAL TRIALS IN THE

PHARMACEUTICAL INDUSTRY

P.L.C. Banks Adria Laboratodes

Dublin, Ohio

Phase III clinical tdals in oncology frequently require ongoing monitoring of the data to satisfy both ethical demands end efficiency considerations. Standard statistical practices exercised in cooperative groups to evaluate interim results are steadily becoming commonplace in the pharmaceutical industry. That is, group