Poor patient adherence in clinical trials may be risky

In the last 10 years, many patients have developed unexpected toxicities from prescription drugs that have been on the market for 5 to 10 years, according to the Consumer Health Information Corp.

Consumer Health Information CEO and President Dorothy L. Smith, PharmD, has reviewed the last 20 years of the patient adherence research in clinical trails. She found:   • Between 1997-1999, patient adherence was not monitored in 53% of clinical trials. Many of these drugs are still on the market.   • Up to 30% of study patients do not take the full dose of the study drug.   • Study patients cannot understand 35% to 94% of Informed Consent documents.   • At least 50% of study patients do not tell the study team they missed doses.   • Many study patients do not realize that missing doses could endanger the lives of millions of people after the drug is approved.   • Poor patient adherence that is undetected in clinical trials may result in a dose that is inaccurate and too high.   Unexpected adverse drug reactions and toxicity could occur when patients in the general population are more adherent than those in the clinical trial. Dr Smith urged clinical trial investigators to:   • Develop a patient adherence strategy for each clinical trial and integrate behavior modification.   • Determine how many doses of every study drug can be missed without jeopardizing the therapeutic outcome.   • Include patient adherence results as an outcome of the clinical trial and publish in the Package Insert.   • Create Informed Consent and patient-friendly programs that patients will understand and make it easier for them to take the study drug.   • Gain patient trust so they provide honest feedback about any problems they had taking the study drug. Always ask, "How would I want to be treated if I were the study patient?"     “Patient adherence in clinical trials must be higher than that of the general population,” Dr Smith told Formulary. “Otherwise, the study does would be too high if the sample size was not increased to maintain power of the study. Unexpected drug toxicities for which FDA is recommending cutting the dose by 50% might be related to the increasing patient adherence in the general population over the last 10 years. To assure health professionals and the public that a dose is safe, patient adherence in clinical trials must be increased to at least 95%.”