Presentation
Use of Surrogates in Human Factors Research – Examples from Studies, Learnings, and Considerations
DescriptionIncluding participants in Human Factors (HF) research who represent the actual intended users of a medical device or combination product is critical to generating and interpreting meaningful data about product usability and safety. Regulatory authorities, including the U.S. Food and Drug Administration (FDA) emphasize that while surrogate participants may be acceptable in certain circumstances, such as during formative testing when the objective is to refine the product design, during validation testing there is less flexibility since the goal is to demonstrate that intended users can use the product safely and effectively for its intended use in the intended use environment. While including intended users as participants in HF research is optimal, sometimes this is not feasible due to real-world constraints such as when the intended users are a rare patient population. Researchers therefore must involve surrogates who represent the intended users on key user attributes that could impact safe and effective use of the product under consideration. It is important to examine whether key user attributes are the only consideration and utilizing an HF Formative study to provide evidence of whether a surrogate group is acceptable or not is necessary.
This presentation will discuss the pros and cons of including surrogate participants in HF Studies. A total of four studies, including two HF Validation Studies and two CUHF Studies, will serve as examples. The studies that will be discussed in this presentation are summarized below.
HF Validation Study 1: Tested a home-use injection kit to treat adult patients with a rare chronic medical condition. A total of 32 adult patient participants were assessed of which 29 participants were surrogates. Surrogates were recruited based on key user attributes representative of the intended patient diagnosis that could impact safe and effective use of the product – having impaired dexterity in the hands.
HF Validation Study 2: Tested an injection device intended for fertility treatment. A total of 30 participants were assessed of which eight participants were surrogates. Surrogates were recruited based on key user attributes representative of the intended patient population, although they did not have the same formal medical diagnosis of infertility. Rather, they reported a history of struggling to become pregnant in an attempt to compare a similar motivational profile.
CUHFS Example 1: CUHFS study with FDA of an automated pen injector for adults with chronic weight management. A total of 100 participants were assessed, including 16 RLD users and 84 surrogates. Surrogates were recruited based on having experience with the platform pen-injector for the RLD for a related, but different medical condition.
CUHFS Example 2: CUHFS study of a pen-injector for pediatric patients and adult patients. A total of 16 pediatric patients were included in the sample of which 13 were surrogates. Surrogates were recruited based on having experience with the RLD platform device for a different medical condition.
Each of these studies will discuss the rationale for the use of surrogates and considerations for selection of appropriate surrogates. In particular this discussion will focus on determining which participant user attributes should be represented by surrogate participants, and in the case of CUHF Studies, RLD product experience as well.
For each example, discussion will also focus on the success of the surrogate selection process, comparison of task performance between surrogate and non-surrogate participants, and overall learnings and takeaways of including surrogates in HF studies. Some key learnings include:
• Surrogates who possess key intended user attributes related to safe and effective use of the product may serve as successful study participants.
• In some cases, even if surrogates possess key intended user attributes, such as experience injecting, lack of relevant disease experience may impact performance due to decreased motivation. However, finding participants with shared medical experiences may help mitigate this.
• In CUHF Studies, finding surrogates with relevant user interface experience is a key attribute and may hold more importance than diagnosis. However, when involving surrogates with experience using the same platform device as the RLD, there may be small device differences in how the same platform device is used or designed. These factors are important to assess in advance.
By examining these examples of the use of surrogates in HF studies, this presentation aims to provide the audience with key takeaways to optimize success when including surrogates as research participants.
This project was supported by the Food and Drug Administration (FDA) of the U.S. Department of Health and Human Services (HHS) through a contract 75F40123D00028/75F40123F19001. The presentation contents are those of the author(s) and do not necessarily represent the official views of, nor an endorsement, by FDA/HHS, or the U.S. Government.
This presentation will discuss the pros and cons of including surrogate participants in HF Studies. A total of four studies, including two HF Validation Studies and two CUHF Studies, will serve as examples. The studies that will be discussed in this presentation are summarized below.
HF Validation Study 1: Tested a home-use injection kit to treat adult patients with a rare chronic medical condition. A total of 32 adult patient participants were assessed of which 29 participants were surrogates. Surrogates were recruited based on key user attributes representative of the intended patient diagnosis that could impact safe and effective use of the product – having impaired dexterity in the hands.
HF Validation Study 2: Tested an injection device intended for fertility treatment. A total of 30 participants were assessed of which eight participants were surrogates. Surrogates were recruited based on key user attributes representative of the intended patient population, although they did not have the same formal medical diagnosis of infertility. Rather, they reported a history of struggling to become pregnant in an attempt to compare a similar motivational profile.
CUHFS Example 1: CUHFS study with FDA of an automated pen injector for adults with chronic weight management. A total of 100 participants were assessed, including 16 RLD users and 84 surrogates. Surrogates were recruited based on having experience with the platform pen-injector for the RLD for a related, but different medical condition.
CUHFS Example 2: CUHFS study of a pen-injector for pediatric patients and adult patients. A total of 16 pediatric patients were included in the sample of which 13 were surrogates. Surrogates were recruited based on having experience with the RLD platform device for a different medical condition.
Each of these studies will discuss the rationale for the use of surrogates and considerations for selection of appropriate surrogates. In particular this discussion will focus on determining which participant user attributes should be represented by surrogate participants, and in the case of CUHF Studies, RLD product experience as well.
For each example, discussion will also focus on the success of the surrogate selection process, comparison of task performance between surrogate and non-surrogate participants, and overall learnings and takeaways of including surrogates in HF studies. Some key learnings include:
• Surrogates who possess key intended user attributes related to safe and effective use of the product may serve as successful study participants.
• In some cases, even if surrogates possess key intended user attributes, such as experience injecting, lack of relevant disease experience may impact performance due to decreased motivation. However, finding participants with shared medical experiences may help mitigate this.
• In CUHF Studies, finding surrogates with relevant user interface experience is a key attribute and may hold more importance than diagnosis. However, when involving surrogates with experience using the same platform device as the RLD, there may be small device differences in how the same platform device is used or designed. These factors are important to assess in advance.
By examining these examples of the use of surrogates in HF studies, this presentation aims to provide the audience with key takeaways to optimize success when including surrogates as research participants.
This project was supported by the Food and Drug Administration (FDA) of the U.S. Department of Health and Human Services (HHS) through a contract 75F40123D00028/75F40123F19001. The presentation contents are those of the author(s) and do not necessarily represent the official views of, nor an endorsement, by FDA/HHS, or the U.S. Government.
Event Type
Oral Presentations
TimeTuesday, March 2410:30am - 11:00am EDT
LocationGramercy
Medical and Drug Delivery Devices