What Makes You Happy?

In many companion animal clinical trials, the subject’s owner is asked to keep a diary. Among the daily entries that each owner will make is their assessment of the effectiveness of the test article on their pet.

This assessment is based on the owner’s perception of changes in their pet’s activity level, demeanor, appetite, or specific ailment. For example, in a study evaluating the effectiveness of a new compound to treat osteoarthritis, the owner might base their evaluation on the ease with which their pet jumps up onto the couch or whether they walk faster than they did before starting the study. While this data is clearly subjective, it often is a major factor in projecting whether the experimental compound will be effective against the target indication in the general population.

During a study’s consenting process, the investigator meets with each owner to explain the study process, describe the experimental compound and possible side effects, and review their responsibilities. Only after a potential study subject’s owner clearly understands the trial’s benefits, risks, and requirements will the investigator decide whether the trial is appropriate for that owner’s pet. Only at that point, can an owner make a reasoned decision to enroll their pet in the study.

A previous column (Animal Pharm No 698), I presented the reasons that owners gave for enrolling their pet in a trial. Of 77 respondents, 63 wanted to improve their pet’s health, 8 were lured by the honorarium, 4 wanted to advance the cause of veterinary medicine, and 2 chose to participate instead of euthanizing their pet. After completing this survey, I wondered whether these owners differed in their levels of satisfaction with having participated in the trial. So, I began searching the literature for information for clues.

Frank W.S.M. Verheggen1 at the University of Maastricht (The Netherlands) interviewed 135 human patients who had participated in one of 26 clinical trials to better understand the factors which contributed to participant satisfaction. Although most of these participants were quite satisfied, there were certain aspects of each trial that dissatisfied them. Unfortunately, Veheggen’s analysis was inconclusive because he was unable to discern convincing relationships between perceived improvements in a patient’s condition and that patient’s satisfaction with having participated in the trial.

Would I have better luck in a survey of veterinary study subject owners and their pets? At the conclusion of our next trial…a multi-site, double-blinded, placebo-controlled study…I surveyed the 267 owners whose pets had participated. The results from 64 who responded were quite interesting.

Each of these owners had been asked to rate their satisfaction on a scale of 1 to 5, with 5 being “very satisfied.” They also were asked if they would participate in another clinical trial. Below is a summary of their feedback, including their perception of the efficacy of the test article.

Very Satisfied (score = 5):

Active treatment/perceived as effective: 21
Active treatment/perceived as not effective: 4
Placebo treatment/perceived as effective: 9
Placebo treatment/perceived as not effective: 13
Total Very Satisfied: 47

Satisfied (score = 4):

Active treatment/perceived as effective: 6
Active treatment/perceived as not effective: 6
Placebo treatment/perceived as effective: 1
Placebo treatment/perceived as not effective: 4
Total Satisfied: 17

Of the 64 respondents, 27 (42%) of those on active treatment perceived their treatment as effective. As you might imagine, these respondents were satisfied with their participation in the trial. What was surprising was that an equal number of participants who perceived their treatment as ineffective were still satisfied with their participation! Why? Further questioning of this latter group elicited 24 responses.

The study helped my pet:

Active treatment/perceived as not effective: 5
Placebo treatment/perceived as not effective: 12
Total: 17

Wanted to support research:

Active treatment/perceived as not effective: 3
Placebo treatment/perceived as not effective: 1
Total: 4

Financial payment:

Active treatment/perceived as not effective: 0
Placebo treatment/perceived as not effective: 2
Total: 2

No answer provided:

Active treatment/perceived as not effective: 0
Placebo treatment/perceived as not effective: 1
Total: 1

Of these same 24 respondents, all but three indicated that they would participate in another clinical trial. Two owners noted that they saw no advantage in participating. The third owner wrote that their pet “does not like being poked with needles.”

This limited data could suggest that pet owners receive an emotional or psychic benefit from study participation quite unrelated to their perception of the test article’s effectiveness.

Addressing this aspect in our recruiting and owner education efforts might result in faster enrollments, closer protocol compliance, and better owner documentation.

1 International Journal for Quality in Health Care, 1998, Vol. 10(4), pages 319-330