Prostate cancer is the second most common type of cancer in men. The use of Prostate Specific Antigen (PSA) for cancer screening, however, has led to the over-diagnosis and over-treatment of prostate cancer. (Please see my earlier post - Screening for Prostate Cancer.)
Implementing Clinical Decision Support (CDS) system has the potential to prevent unnecessary screening, reduce patient harm, and lower health care costs.
Workflows and Trigger Events
To implement a successful CDS, a good understanding of the clinical workflow is crucial. A typical (simplified) office workflow for physicians is as follows:
- Patient arrives at office and registers
- RN or Medical Assistant takes vitals
- Patient is ushered in exam room
- PCP either reviews chart before entering exam room (to refresh memory) or reviews chart before making recommendations
- PCP makes recommendations to patient
- PCP places orders (medications or labs) in the EHR
- PCP completes encounter record
Item 4 and 6 (those highlighted in green in the flowchart) in the above workflow are targets for CDS.
Providers generally review the chart before talking to patients. Since, some providers may be unaware of the new prostate cancer screening recommendations, opening the patient's chart in the EHR should be a CDS trigger. This CDS can be in the form of a disruptive alert, or preferably a visual "non-disruptive" alert on the patient review (or snapshot) screen.
A second CDS opportunity when providers use Computerized Provider Order Entry (CPOE) functionality enter orders. The trigger would be when a provider places an order for a PSA test. The EHR can alert the provider about the new guidelines, and/or if a prior PSA test result exists.
An info-button next to an elevated PSA value can also be implemented. This may help providers interpret the PSA values in accordance to the guidelines.
Required Data for CDS
Several elements of data are required to create an effective CDS:
- Patient Age
- Problem list and Past Medical History:
- To calculate 10 year survival probability using Charleson comorbidity index (or other survival scoring systems)
- To look for prior diagnosis of prostate cancer,
- To estimate if patient is at high risk for prostate cancer (e.g. certain genetic conditions)
- Family history - to determine if patient is high risk, especially if he has 1st degree relatives with prostate cancer
- Last PSA result, and date test was performed (if available)
Risk Stratification Algorithm
The risk stratification algorithm combines the Prostate Cancer Screening recommendations from the major clinical societies including USPSTF, AUA, ACS and ACP. This is a basic algorithm, which will need testing before implementation.
Measuring Effectiveness of CDS
It is essential to measure the effectiveness of any new CDS pathway to determine that it is producing the anticipated results. A simple way to test the PSA screening CDS is by measuring the number of PSA tests ordered in patients over 50 years old. One important exclusion criteria (i.e. do not count PSA tests ordered on patients) is patients with prostate cancer. PSA is sometimes used to follow treatment and recurrence of prostate cancer. Furthermore, CDS override reasons should be monitored, and if justified, the reason should be built into the exclusion criteria.
Prostate cancer screening using PSA test carries more risk than benefit. Implementing a well designed clinical decision support system will reduce unnecessary screening, and promote shared decision making based on risk factors, thereby reducing patient harm.