ASCO GU 2018: The Association Between Physician Trust and Prostate Specific Antigen Screening: Implications for Shared Decision Making.

San Francisco, CA ( Following the poor feedback in response to the 2012 USPSTF recommendations regarding PSA screening, updated USPSTF guidelines have pulled back their grade recommendation from a “D” to a “C” – “the USPSTF recommends that clinicians inform men ages 55 to 69 years about the potential benefits and harms of prostate-specific antigen (PSA)–based screening for prostate cancer. The decision about whether to be screened for prostate cancer should be an individual one.”

While most guidelines from international urology associations now recommend PSA screening for a selected age population between 50-70 years of age, shared decision making is a key portion of all the guidelines – a discussion between the physician and the patient regarding the risks and benefits of PSA screening. However, this shared decision making is based on a trusting relationship between patient and their physician, often their primary care physician.

In this abstract, the authors utilize the HINTS (Health Information National Trends Survey), a population-based survey of people living in the United States, to assess the degree to which an individual’s trust in cancer information from their physician compared to internet-based information, and its impact on the likelihood to discuss and undergo PSA-screening. This was a cross-sectional study, so there was no long term follow-up.

With regards to trust, respondents had an option of ‘a lot’, ‘some’, ‘a little’, and ‘not at all.’ A total of 5069 eligible respondents (men aged > 18 years of age) were assessed.

Of these, 3,606 (71.1%) men reported trusting cancer information from their physician ‘a lot’, 1,186 (23.4%) reported trusting it ‘some’, 219 (4.3%) ‘a little’, and 58 (1.1%) ‘not at all’. White, married men with higher levels of education and income were more likely to report a higher degree of trust in their physician. Similarly, men with health insurance or born in the USA were more likely to have trust in their physician.

In contrast, 767 (15.1%) reported ‘a lot’ of trust in cancer information from the internet, 2543 (50.2%) reported ‘some’ trust, 1044 (20.6%) reported ‘a little’ trust, 448 (8.8%) reported ‘not at all’, and 267 (5.3%) didn’t answer the question.

Of all eligible men, 2,655 (52.4%) men had received PSA-screening at the time of the survey. The degree of trust an individual had in their physician for cancer information was strongly associated with their likelihood of having received PSA-screening: among men who reported ‘a lot’ of trust, 54.9% underwent screening, 48.6% among men who reported ‘some’ trust, 38.4% among men who reported ‘a little’ trust, and 27.6% among men who reported ‘not at all’ trusting their physician (trend p<0.0001). Importantly, the degree to which an individual trusted cancer information from the internet was also associated with having received PSA-screening (p=0.005), albeit with an insignificant trend (p=0.07). After multivariable adjustment, these significant results persisted for degree of physician trust (vs ‘a lot’: ‘some’ OR 0.80, 95%CI 0.66-0.97; ‘a little’ OR 0.61, 95%CI 0.41-0.90; ‘not at all’ OR 0.33, 95%CI 0.15-0.73) but not for trust in information from the internet.

This study highlights the important of the physician-patient relationship in the shared decision making process. It may also highlight the underlying discrepancies in PSA screening and subsequent prostate cancer diagnoses in some underserved populations, in which the physician-patient relation isn’t as strong.

Limitations / Discussion Points:

1. As a cross-sectional study, recall bias is a significant risk. It is unclear how much of an impact this would have on the outcomes though.
2. Other factors, including family history and voiding symptoms are not captured. This may play a role in PSA screening.
3. Nature of the physician counseling involved in shared decision making is not clear. Certain physicians may insert their own biases into the decision-making process which may impact the PSA screening process.
4. The study may represent reverse causality – patients may have increased trust in physicians who recommend PSA screening and they consider to be thorough.

Presented by: Zachary Klaassen, MD

Written by: Thenappan Chandrasekar, MD, Clinical Fellow, University of Toronto, Twitter: @tchandra_uromd at the 2018 American Society of Clinical Oncology Genitourinary (ASCO GU) Cancers Symposium, February 8-10, 2018 - San Francisco, CA