A Call to Action – Inform Patients of Clinical Trials
Randomized, controlled, double-blind clinical trials are considered the gold standard by which healthcare professionals evaluate the clinical efficacy of a drug or a class of drugs. They are the only study design that can truly prove the cause and effect between a drug and a particular outcome. Therefore, providers greatly rely on them to make treatment decisions. When clinical trials include only a small percentage of elder subjects, it is challenging to apply the results to all older adults, particularly considering their vastly different health profiles and higher prescription drug utilization compared with younger people.
Low Representation in Clinical Trials
Although hypertension is considered a risk factor for cardiovascular disease, it is only a surrogate marker. The pool of eligible studies can be further reduced by excluding those with poor methodology (eg, inadequate randomization, blinding, or handling of dropouts). Nine quality primary studies were found with meaningful outcomes of interest. Two of these studies excluded subjects aged older than 70. The mean age in the eligible studies was 60 to 67 years old. Only one study reported further stratification by age group. The lack of studies focusing on the senior population is concerning when we consider that this is a class of drugs that would be expected to be highly utilized in the elder population.
A similar situation exists for inhaled corticosteroids. Outcomes available for this class of drugs include reduction and exacerbation of respiratory symptoms and mortality. Studies evaluating only lung function were eliminated from consideration because this is a surrogate outcome that does not necessarily equate to symptom improvement. Three secondary studies and one primary study were found for the treatment of asthma, and four secondary studies were found for the treatment of chronic obstructive pulmonary disease (COPD). For the secondary asthma trials, the mean age was listed as between 8 and 55 years old. The primary study included asthmatic children between the ages of 6 and 15. For the COPD studies, the patient population was described as adult. Examination of the details of the included COPD studies in the secondary trials revealed an age range between 53 and 73 years old, with lack of stratification.
Similar to the studies on angiotensin receptor blockers, the lack of studies focusing on the results of inhaled corticosteroids in elders is an issue given the high utilization of these drugs in this population.
Who Are Considered Elders?
Special Considerations in Elders
What should clinicians who prescribe drugs for elders do when clinical trials lack sufficient information about the results of the use of certain drugs in the older population? Results from clinical trials in which the elder population is noticeably underrepresented should be used with caution when making treatment decisions. There is often not enough information to ascertain whether outcomes or side effects would differ in important ways from those seen in younger patients. Determining starting dosages and titration schedules for individual patients as well as expectations of risk vs. benefit is largely left to a clinician’s judgment and personal experience. Even product-specific information is often lacking in this regard. Physicians and other clinicians may find it appropriate to adhere to the old mantra to “start low, go slow” when treating elder patients.
A Call to Action
The practice of evidence-based medicine in the geriatric arena requires careful consideration. A knowledge gap exists, one that will be filled only by including adequate numbers of elder subjects in clinical trials. Practitioners can answer the call to action by offering information about trial recruitment to their patients, providing honest answers to their questions, and encouraging their participation.
— Karen Martin, PharmD, MBA, CGP, is board certified in geriatric pharmacy and a senior drug information specialist for WellPoint, Inc.
2. U.S. Census Bureau. State & county quickfacts, USA. Available at: http://quickfacts.census.gov/qfd/states/00000.html . Accessed July 8, 2010.
3. Delafuente JC. Pharmacokinetic and pharmacodynamic alterations in the geriatric patient. Consult Pharm. 2008;23(4):324-334.
4. Herrera AP, Snipes SA, King DW, et al. Disparate inclusion of older adults in clinical trials: Priorities and opportunities for policy and practice change. Am J Public Health. 2010;100 Suppl 1:S105-S112.