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Randomised controlled trial
Delivering a decision support intervention about PSA screening to patients outside of clinical encounters is ineffective in promoting informed decision-making
  1. Paul K J Han
  1. Center for Outcomes Research and Evaluation, Maine Medical Center, Portland, Maine, USA
  1. Correspondence to Dr Paul K J Han, Center for Outcomes Research and Evaluation, Maine Medical Center, 509 Forest Avenue, Portland, ME 04101, USA; hanp{at}

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Prostate-specific antigen (PSA) screening is a commonly utilised but controversial intervention of uncertain clinical value. Major professional organisations have therefore recommended that patients be fully informed about the pros, cons, and uncertainties of PSA screening, and enabled to decide based on their own values—a process known as informed decision-making (IDM).1 The US Preventive Services Task Force and other influential groups have further highlighted the need for shared decision-making (SDM)—the collaborative engagement of clinicians in this process.2 Nevertheless, IDM and SDM have not been the norm in clinical practice.

Well-known barriers to IDM and SDM include limited clinical time and resources for these efforts. Patient decision support interventions (DESIs) can help overcome these barriers, and have demonstrated efficacy in improving IDM in PSA screening. Whether DESIs are actually effective in ‘real world’ clinical practice, however, is unknown and depends on whether they can be successfully delivered to patients, either in or outside of clinical encounters.


This study was a randomised controlled trial comparing the effectiveness of alternative strategies for delivering a PSA screening DESI to screening-eligible patients, outside of clinical encounters: (1) mailing the DESI in DVD format; (2) offering a shared medical appointment (SMA) to view the DESI with other patients; (3) both options (DESI+SMA); and (4) neither option (control). Randomly selected men (aged 50–75 with no history of prostate cancer, PSA screening in 10 months or PCP visits in 3 months) in two distinct primary care practice settings were sent a mailing that included information about the controversial nature of PSA screening and the need for IDM, along with the intervention to which patients were assigned. Self-reported DESI viewing, SMA attendance, provider contact, and PSA screening knowledge and attitudes at 4 months were ascertained by survey, and PSA screening uptake at 12 months was ascertained by medical record review.


Of 4028 randomly selected men, 701 were ineligible, 777 opted out, 2550 participated and 2001 completed surveys (76.6% participation rate, 60.1% survey response rate). DESI viewing was low overall and did not differ between the DESI (16%) and DESI+SMA (15%) groups; SMA attendance also did not differ between the SMA (5%) and DESI+SMA (3.6%) groups. There were no significant between-group differences in PCP visits or PSA screening discussions at 4 months, or PSA uptake at 12 months (21%, 24%, 22%, and 21% for the DESI, SMA, DESI+SMA and control groups). However, patients who viewed the DESI had greater PSA uptake (30% vs 21%, p=0.01), patient-provider screening discussions (57% vs 41%, p=0.02), and PSA screening knowledge, and less positive screening attitudes.


This well-done study adds to mounting evidence on the challenges of achieving IDM through the use of DESIs.3 Alternative methods for delivering a DESI directly to patients—outside of clinical encounters—resulted in low DESI use, and no effects on PSA screening decisions. DESI use did lead to greater knowledge and other outcomes consistent with IDM as well as SDM, including less positive screening attitudes, greater patient-provider screening discussions, and—unexpectedly although not inconsistent with IDM—greater PSA screening. However, few patients used the DESI.

The study raises several questions for future research. Could aspects of the delivery method—for example, the initial mailing describing the controversial nature of PSA screening—have reduced DESI use? What patient-level and system-level factors limit DESI use? Are there more effective methods of promoting DESI use—for example, involving physicians or tying DESI use to clinical encounters? How did patients who opted out of the study differ from participants? Did PSA screening knowledge—or other unmeasured indicators of IDM—differ among the groups? This question is critical given that the effectiveness of interventions aimed at promoting IDM/SDM cannot be judged by level of screening uptake.

Nevertheless, the study raises doubts about the effectiveness of interventions aimed at promoting IDM by delivering DESIs directly to patients, outside of clinical encounters. Involving clinicians in the delivery process may be necessary—and desirable as a means of promoting clinician-patient engagement in SDM—despite the associated costs of this approach. The larger question, however, is how aggressive such efforts ought to be in the case of PSA screening, given the degree of scientific uncertainty about its value, and growing skepticism about its routine use.2

Implications for practice

Promoting informed decision-making in PSA screening requires more than simply delivering DESIs to patients outside of clinician-patient encounters.


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  • Competing interests None declared.

  • Provenance and peer review Commissioned; internally peer reviewed.

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