Delayed Telephone Consent in Emergency Medicine Research


To the Editor:

We appreciate the work of Offerman and colleagues,[1] which describes the process of enrolling emergency department (ED) patients in a study by identifying them using the ED record and contacting them by telephone after the ED visit to request consent. We agree with the authors' conclusion that delayed telephone consent is generally ethical and efficient, but offer the following observations.

The investigators report that of 506 eligible patients identified by emergency providers in the ED, 501 (99.0%) patients or their surrogates were successfully reached by phone using phone numbers in the ED medical records, and 500 (99.8%) consented to the study. These very high rates of reaching and consenting patients are not consistent with our experience or that of others performing ED-based research.

A recent large study of medication adherence among ED patients obtained 1-week follow-up for 86% of patients (3,386 of 3,940).[2] In the medication adherence study contact information was obtained via in-person interview, and patients received $10 gift cards for completing follow-ups. Our own experience conducting research on older adults is similar; short-term follow-up can be achieved for 85% to 90% of older patients if one obtains comprehensive contact information in the ED and makes considerable efforts to reach the patient.[3] When we used similar methods to that of Offerman et al. (i.e., making calls to patients using information from the ED record), only approximately 50% of patients or surrogates were contacted.[4] The other prior similar study referenced by Offerman et al. reached 80% of patients (167 of 209) using delayed consent, which was similar to the 81% (180 of 221) reached following ED consent.[5] The much higher rates of contact reported by Offerman et al. may in part be because of sociodemographic differences in the study population or because the study question is essentially a continuation of the patient's clinical care. Regardless of the explanation, a 99% contact rate is unusually high, and future researchers should neither expect to obtain nor be criticized for not obtaining a similar response rate. Further, we think it unlikely that deferred consent is likely to provide consistently higher follow-up rates than ED consent.

The other conclusion the authors draw from their study is that this approach is ethical. We agree that in most situations making an unsolicited phone call to request study participation following an ED visit is ethical, but the details matter. Calls to home phones for individuals who have recently visited the ED for complaints related to substance abuse or an early pregnancy may be unwelcome and unethical, even if the study does not contain an intervention.