Search

The Digitalis Investigation Group (DIG) trial was the first large simple trial conducted by the National Heart, Lung, and Blood Institute in conjunction with the Department of Veterans Affairs. A large simple trial is a major undertaking. Simplification at the sites requires careful planning and discipline. Lessons learned from the DIG trial were: (1) keep a large simple trial very simple and keep all study procedures very simple; (2) ancillary studies are important and can complement a large simple trial but require careful advanced planning; (3) anticipate special needs when shipping study drugs internationally; (4) regional coordinating centers can be very useful; (5) recruit as many capable sites as possible; (6) provide research-inexperienced sites/investigators with extra help to obtain federalwide assurance statements from the Office for Human Research Protections and institutional review board approvals; (7) adequately reimburse sites for the work completed; (8) maintain investigator enthusiasm; (9) monitor the slow performers and sites with numerous personnel changes; (10) choose an endpoint that is easy to ascertain; (11) keep the trial simple for participants; and (12) plan early for closeout and for activities between the end of the trial and publication of results.

Patient surveys are commonly distributed at the end of a multicenter clinical trial. This Antiarrhythmics Versus Implantable Defibrillators (AVID) substudy prospectively explored the relationship between methods used in distributing a survey and the quantity of responses received. AVID was a multicenter, randomized trial comparing survival in arrhythmia patients treated with antiarrhythmic drugs versus implantable defibrillators. At study termination, a patient satisfaction survey was mailed to the 664 surviving participants. Questions included reasons for study participation, study benefits and problems and quality of care. Survey mailings were stratified by four factors in a 2×2×2×2 factorial design: delivery mode (overnight vs. regular mail), certificate of appreciation, timing of administration (“early” vs. “late”) and cover letter signed by a physician versus coordinator. Patients were randomly assigned to received one of 16 combinations of these four factors. Clinical characteristics and response rates were evaluated. Patients were more likely to return surveys delivered by overnight mail (75% vs. 68%, p=0.04), with no certificate of appreciation enclosed (75% vs. 68%, p=0.05) and administered close to the time of study closeout (79% vs. 72%, p=0.085). Compared to the 184 nonrespondents, the 456 (71%) respondents were older, Caucasian, lived with others, were high school graduates and less likely to have Medicare/Medicaid or HMO insurance (p

The Treatment of Mild Hypertension Trial was a randomized, double-blind clinical trial conducted from 1986 to 1992 comparing the efficacy of six antihypertensive treatment regimens in 902 participants with stage I hypertension. To satisfy a secondary objective of the study, follow-up information on mortality and cardiovascular morbidity was collected. For this objective the aim was to ascertain the vital and cardiovascular event status as of the last day of the trial. This was accomplished by inviting each participant to attend a closeout visit shortly after the closeout date. In addition to serving as verification of vital status, this visit allowed data collection on nonfatal events that occurred between the last clinic visit and the closeout date. During this visit the patient was unblinded to study medication and given a medical summary of their participation during the trial, as well as a bottle of open-label medication. The advantages of a closeout visit are discussed along with a call for studies to provide clearer definitions of lost to follow-up and censoring times used in life-table analyses, especially when the primary event includes both fatal and nonfatal events. Control Clin Trials 2001;22:56–61

Closeout of a clinical trial, whether carried out to its original completion of full accrual and attendant follow-up or stopped prematurely because of early indications of efficacy or adverse toxicity, presents challenges in many areas. Closing a clinical trial that fails to adequately accrue and/or successfully follow up patients may exacerbate these problems. The issues involved in the early termination of the Low-Dose Oral Alpha Interferon Trial are described. Control Clin Trials 2001;22:49-55

The Digitalis Investigation Group (DIG) trial was a large simple trial (LST) begun in 1990 as a collaboration between the National Heart, Lung, and Blood Institute and the Department of Veterans Affairs (VA) Cooperative Studies Program (CSP). Its primary objective was to determine whether digitalis had beneficial, harmful, or no effect on total mortality in patients with congestive heart failure and an ejection fractionor =0.45. The Perry Point VA CSP Coordinating Center served as the trial's data coordinating center (DCC). The DCC was involved in all phases of the study from planning and design, organization and start-up, and patient recruitment and follow-up through closeout, final analyses, and manuscript preparation. While DCC responsibilities for an LST are basically the same as for other multicenter randomized clinical trials, their size and the inclusion of many inexperienced research sites can add a complexity that the DCC must be prepared to handle from the beginning. This paper describes the role of the DCC in the DIG trial.