Abstract
Background
Patients’ beliefs and attitudes towards a treatment can affect treatment response. In unblinded trials this can affect outcomes.
Aims
The aim of this analysis was to examine the association between treatment preference and expectation, and outcome in a trial of pain treatments.
Methods
In a randomised trial (ISRCTN67013851) of four treatments for chronic widespread pain, participants were asked which they would prefer, and what improvement they expect from each. The proportion of participants reporting positive health outcomes at three time-points after treatment were compared between those matched or unmatched with their preference, and between those with and without expectation for improvement. Odds ratios were calculated adjusted for baseline characteristics associated with preference and expectation.
Results
442 participants were recruited to the trial (69.5% female). The proportion reporting positive outcome among participants matched to their preference compared to those unmatched was: 33.3% vs 34.4% at end of treatment (adjusted OR 0.80, 95% CI 0.44–1.46), 34.4% vs 29.0% at 3 months (aOR 1.23, 0.67–2.26), and 34.8% vs 30.3% at 2 years (aOR 1.31, 0.70–2.46). The proportion of participants reporting positive outcome among those expecting improvement compared to those not was: 36.6% vs 15.0% at end of treatment (aOR 2.03, 1.07–3.85), 34.1% vs 13.2% at 3 months (aOR 2.31, 1.22–4.38), and 32.8% vs 19.1% at 2 years (aOR 1.16, 0.67–2.36).
Conclusions
Treatment preference had no clear effect on outcomes, but expectation did. These results could inform future approaches to management, while researchers assessing treatments should take into account this expectation effect.
Patients’ beliefs and attitudes towards a treatment can affect treatment response. In unblinded trials this can affect outcomes.
Aims
The aim of this analysis was to examine the association between treatment preference and expectation, and outcome in a trial of pain treatments.
Methods
In a randomised trial (ISRCTN67013851) of four treatments for chronic widespread pain, participants were asked which they would prefer, and what improvement they expect from each. The proportion of participants reporting positive health outcomes at three time-points after treatment were compared between those matched or unmatched with their preference, and between those with and without expectation for improvement. Odds ratios were calculated adjusted for baseline characteristics associated with preference and expectation.
Results
442 participants were recruited to the trial (69.5% female). The proportion reporting positive outcome among participants matched to their preference compared to those unmatched was: 33.3% vs 34.4% at end of treatment (adjusted OR 0.80, 95% CI 0.44–1.46), 34.4% vs 29.0% at 3 months (aOR 1.23, 0.67–2.26), and 34.8% vs 30.3% at 2 years (aOR 1.31, 0.70–2.46). The proportion of participants reporting positive outcome among those expecting improvement compared to those not was: 36.6% vs 15.0% at end of treatment (aOR 2.03, 1.07–3.85), 34.1% vs 13.2% at 3 months (aOR 2.31, 1.22–4.38), and 32.8% vs 19.1% at 2 years (aOR 1.16, 0.67–2.36).
Conclusions
Treatment preference had no clear effect on outcomes, but expectation did. These results could inform future approaches to management, while researchers assessing treatments should take into account this expectation effect.
Original language | English |
---|---|
Pages (from-to) | 161-170 |
Number of pages | 10 |
Journal | Canadian Journal of Pain |
Volume | 1 |
Issue number | 1 |
Early online date | 11 Oct 2017 |
DOIs | |
Publication status | Published - 2017 |
Bibliographical note
The following are members of the MUSICIAN study team: Gary Macfarlane (Principal Investigator), John McBeth (Investigator), Deborah Symmons (Investigator), Karina Lovell (investigator), Philip Keeley (Investigator), Phil Hannaford (Investigator), Chrysa Gkazinou (Trial manager), Marcus Beasley (Research Assistant), Elizabeth Jones (PhD student), Gordon Prescott (Statistician), and Steve Woby (Investigator). We are grateful to the practices and patients in Aberdeen city and Cheshire, which participated in the study: Cardenmedical centre, Elmbank medical practice, Great Western Road medical practice, Garthdee medical group, Readesmoor medical group practice, Lawton House surgery, Bollington medical practice, Park Lane surgery. The Scottish Primary Care Research Network facilitated access to patient information at the practices in Aberdeen city. Charlie Stockton was the study manager and Ashraf El-Metwally an Investigator during the setting up and for part of the conduct of the study. John Norrie was originally an investigator of the MUSICIAN study while Director of the Centre for Health Care Randomised Trials (CHART) at the University of Aberdeen. We are grateful for the input of members of the Health Services Research Unit (HSRU) at The University of Aberdeen in the conduct of the study: Alison MacDonald and Gladys McPherson. We are grateful to the project assistants who worked on the survey: Dev Acharya, Jennifer Bannister, Flora Joyce, Michelle Rein., Karen Kane, and Rowan Jasper. Alison Littlewood was responsible for study management at the Cheshire site. Finally, we thank the independent members of the trial steering committee (Professor Matthew Hotopf, Professor Tracey Howe, Professor Martin Underwood) and data monitoring committee (Dr. Marwan Bukhari, Professor Hazel Inskip, Dr. Chris Edwards).
Funding details
The study was funded by Arthritis Research UK, grant number 17292.
Keywords
- placebo response
- treatment preference
- expectation
- randomised controlled trials
- treatment effect
- non-specific effects