Consent document translation expense hinders inclusive clinical trial enrolment

Abstract

Patients from historically under-represented racial and ethnic groups are enrolled in cancer clinical trials at disproportionately low rates in the USA^1-3. As these patients often have limited English proficiency^4-7, we hypothesized that one barrier to their inclusion is the cost to investigators of translating consent documents. To test this hypothesis, we evaluated more than 12,000 consent events at a large cancer centre and assessed whether patients requiring translated consent documents would sign consent documents less frequently in studies lacking industry sponsorship (for which the principal investigator pays the translation costs) than for industry-sponsored studies (for which the translation costs are covered by the sponsor). Here we show that the proportion of consent events for patients with limited English proficiency in studies not sponsored by industry was approximately half of that seen in industry-sponsored studies. We also show that among those signing consent documents, the proportion of consent documents translated into the patient's primary language in studies without industry sponsorship was approximately half of that seen in industry-sponsored studies. The results suggest that the cost of consent document translation in trials not sponsored by industry could be a potentially modifiable barrier to the inclusion of patients with limited English proficiency.

Extended Data Figure 1.

Comparison of the proportion of consent events based on primary language and English proficiency in interventional industry versus non-industry sponsored studies. A. Blue indicates the proportion of consent events for patients with English as their primary language. Yellow indicates the proportion of consent events for patients with a primary language other than English in industry sponsored studies (top bar) versus non-industry sponsored studies (bottom bar) (8.2% versus 4.0%, p<0.001). B. Blue indicates the proportion of consent events for patients with English as their primary language. Red indicates the proportion of consent events for patients with limited English proficiency in industry sponsored studies (top bar) versus non-industry sponsored studies (bottom bar) (5.6% versus 2.5%, p<0.001). Logistic regression models with Generalized Estimating Equations clustered by patient unique identifier were used to test comparisons above, p-values reported are two-tailed.

Extended Data Figure 2.

Comparison of the percentage of patients signing consent documents per study between industry and non-industry sponsored studies. The X axis depicts the percentage of patients signing consent documents for each study who had a primary language other than English in industry (a) and non-industry sponsored studies (b). Each study is represented by a row in the Y axis. The rows are taller for non-industry sponsored studies compared to industry sponsored studies as there are fewer of them. Green denotes the percentage of patients who signed consent in their primary language, pink represents the percentage of patients signing consent documents in a language different than their primary language and red represents the percentage of patients with limited English proficiency signing consent document in a language different than primary.

Figure 1.

Consent process and cost allocation of consent document translation. An investigator meeting an eligible patient for a clinical trial should assess the patient’s (or parent/guardian’s) comfort with signing an English consent document. If patient (or parent/guardian) is not comfortable signing consent documents in English, the investigator should translate the consent documents. Depending on the study funder, this cost can be either completely passed on to the industry sponsor, potentially covered by the industry sponsor or covered completely by the investigator.

Figure 2.

Consent events included in the study. Consent event data for patients who signed consent documents for Cancer Center studies from 2013 to 2018 were included in our analysis if they had a medical record number in our electronic health system as well as a documented primary language (n=12,082). Patients were considered to have English as their primary language (English Primary, n=11,340) or to have a primary language other than English (n=742). Patients with a primary language other than English were considered to have limited English proficiency if there was evidence for the use of an interpreter in the electronic health record. The racial/ethnic distribution of patients is depicted by color with the representative colors described in the box on the lower left.

Figure 3.

Comparison of the proportion of consent events based on primary language and English proficiency in industry versus non-industry sponsored studies. a. Blue indicates the proportion of consent events for patients with English as their primary language. The bracketed areas indicate the proportion of consent events for patients with a primary language other than English in industry sponsored studies (top bar) versus non-industry sponsored studies (bottom bar) (8.1% versus 4.4%, p<0.001). Green indicates the proportion of consent events for patients with a primary language other than English signing consent documents in a language different than their primary in industry sponsored studies (top bar) compared to non-industry sponsored studies (bottom bar) (3.5% versus 3.2%, p=0.391). Yellow indicates the proportion of consent events for patients with a primary language other than English signing consent documents in their primary language in industry sponsored studies (top bar) compared to non-industry sponsored studies (bottom bar) (4.6% versus 1.2%, p<0.001). b. Blue indicates the proportion of consent events for patients with English as their primary language. The bracketed areas indicate the proportion of consent events for patients with limited English proficiency in industry sponsored studies (top bar) versus non-industry sponsored studies (bottom bar) (5.5% versus 2.8%, p<0.001). Purple indicates the proportion of consent events for patients with limited English proficiency signing consent documents in a language different than their primary in industry sponsored studies (top bar) compared to non-industry sponsored studies (bottom bar) (1.8% versus 1.8%, p=0.643). Red indicates the proportion of consent events for patients limited English proficiency signing consent documents in their primary language in industry sponsored studies (top bar) compared to non-industry sponsored studies (bottom bar) (3.7% versus 1.0% p<0.001). Logistic regression models with Generalized Estimating Equations clustered by patient identifier compared the proportions above, p-values reported are two-tailed.

Figure 4.

Comparison of the proportion of consent events by language. a. Orange bars indicate the proportion of consent events for which patients with a primary language other than English signed consent documents in their primary language in industry versus non-industry sponsored studies (light orange, 56.2% versus 27.4%, p<0.001; dark orange, 57.6% versus 28.1%, p<0.001). Purple bars indicate the proportion of consent events for which patients signed consent documents in a language different than primary in industry versus non-industry sponsored studies (43.8% versus 72.6%, p<0.001). Blue indicates the proportion of consent events for which patients signed consent documents in English in industry versus non-industry sponsored studies (42.4% versus 71.9%, p<0.001) b. Yellow bars indicate the proportion of consent events for which patients with limited English proficiency signed consent documents in their primary language in industry versus non-industry sponsored studies (light yellow, 68.1% versus 34.1%, p<0.001; dark yellow, 68.1% versus 35.1%, p<0.001). Grey bars indicate the proportion of consent events for which patients signed consent documents in a language different than primary in industry versus non-industry sponsored studies (31.9% versus 65.9%, p<0.001). Blue bars indicate the proportion of consent events for which patients signed consent documents in English in industry versus non-industry sponsored studies (30.6% versus 64.9%, p<0.001). Logistic regression models with Generalized Estimating Equations clustered by patient unique identifier compared the proportions above, p-values reported are two-tailed. c. Among patients with a primary language other than English signing consent documents for both an industry and a non-industry sponsored study, 10 (green) signed in their primary language and 24 signed in a language different than primary for both (purple). Of the 18 patients who signed consent documents in discrepant languages, 16 (pink) signed in their primary language in the industry sponsored study versus 2 (blue) in the non-industry sponsored study (McNermar’s test, p=0.002).

Figure 5.

Odds Ratios for patients with a primary language other than English and with limited English proficiency signing consent documents in non-industry sponsored studies compared to patients with English as their primary language across the different Departments. Odds Ratios for patients with a primary language other than English (dark grey cells) and limited English proficiency (white cells) of signing consent document in any language (light grey cells) and in the patient’s primary language (white cells) were calculated using a logistic regression model with Generalized Estimating Equations clustered by patient unique identifier. Dot denotes odds ratio and bars represent 95% CI. *OR could not be calculated as no consent documents were translated into patient’s primary language. ^ƗOR could not be calculated because there were no patients with a primary language other than English or limited English proficiency who signed consent documents in their primary language in industry sponsored studies. Abbreviations; OR, Odds Ratio, CI; confidence Interval.