Biomedical subjects

DIG Investigators

Publications and source records attributed to DIG Investigators.

6 recordsLinked to original sources

PubMed2003

Lessons learned from the DIG trial.

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.

Canada↗

PubMed2003

The role of the data coordinating center in the IRB review and approval process: the DIG trial experience.

Before any clinical trial can begin to recruit patients, participating clinical centers must obtain approval from their institutional review board (IRB). When studies are federally funded, such as by the U.S. Department of Health and Human Services (DHHS), centers must also have or obtain a federal compliance agreement from the Office of Human Research Protections (formerly the Office for Protection from Research Risks [OPRR]). The Digitalis Investigation Group trial was a large, international, double-blind, DHHS-funded randomized trial on the effect of digoxin on mortality in heart failure. Due to the anticipated number of centers (>200), the study's data coordinating center (DCC) was requested to assume additional responsibilities that included: (1) acting as a liaison between the OPRR and all study centers; (2) reviewing and correcting all assurance statements before submission to the OPRR; (3) reviewing and approving all centers' informed consent forms; and (4) helping the many research-inexperienced centers to establish IRBs or to locate an IRB in their region that would accept IRB responsibility for them. Although a heavy burden was placed on the DCC, the IRB and OPRR approval process was probably shortened by many weeks at those centers not already possessing a federal compliance agreement. This enabled the study to be completed on schedule and within budget.

Canada↗

PubMed2003

The use of regional coordinating centers in large clinical trials: the DIG trial.

The Digitalis Investigation Group (DIG) trial was a large simple clinical trial that involved 302 participating centers in the United States and Canada. In order to encourage participation by Canadian investigators, to provide additional help to what were expected to be largely research-inexperienced investigators in Canada, and to provide the study's data coordinating center with resources in Canada to deal with potentially different rules, regulations, and cultural differences, regional coordinating centers were established in four regions of Canada: the maritime provinces, Quebec, Ontario, and western Canada. Canadian centers recruited significantly better than their U.S. counterparts and had slightly better retention and follow-up. While it is not possible to declare that the regional coordinating centers were responsible for this improvement, it is believed that these regional centers did play a role. This role included being able to identify investigators who could be expected to do well, providing one-on-one training and instruction to investigators, and being able to solve problems and implement change in the relatively fewer centers in their regions. The regional coordinating center also reduced the intensity of the workload on the data coordinating center by serving as the primary point of contact for Canadian investigators. The use of regional coordinating centers in studies with a large number of participating centers is highly recommended.

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PubMed2003

The role of the pharmacy coordinating center in the DIG trial.

Large simple trials (LSTs) emerged in response to the need for large sample sizes to answer important clinical questions in which treatments have a moderate effect on clinical endpoints. Between 1991 and 1996 the National Heart, Lung, and Blood Institute and the Department of Veterans Affairs (VA) Cooperative Studies Program conducted an LST entitled "Digitalis Investigation Group (DIG): Trial to Evaluate the Effect of Digitalis on Mortality in Heart Failure." The VA Cooperative Studies Program Clinical Research Pharmacy Coordinating Center served as the DIG pharmacy coordinating center (PCC). As a direct result of involvement in the DIG trial, the PCC identified the need for an increased emphasis on computerization and automated support of clinical trials, especially LSTs.

Canada↗

PubMed2003

The role of the data coordinating center in the DIG trial.

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 fraction < or =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.

Canada↗

PubMed2003

Overview of the DIG trial.

Congestive heart failure is a major public health problem in the United States, Canada, and other Western countries. The Digitalis Investigation Group (DIG) trial was a randomized, double-blind placebo-controlled trial that evaluated the effects of digoxin on all-cause mortality and on hospitalization for heart failure in patients with heart failure and left ventricular ejection fraction < or =0.45 with normal sinus rhythm. It was designed as a large simple trial. There were 6800 patients entered into the main study over a 31.5-month recruitment period at 302 participating centers in the United States and Canada. All patients were followed for a minimum of 28 months. In order for this study to succeed, many groups had to work together successfully. In this supplement, we present practical aspects of organizing and conducting a large simple trial such as DIG.

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