2008 US Preventive Services Task Force Recommendations and Prostate Cancer Screening Rates FREE

To the Editor: The US Preventive Services Task Force (USPSTF) recently drafted a grade D recommendation against prostate-specific antigen (PSA)–based screening for prostate cancer.¹ If this recommendation becomes final, how it will affect clinical practice remains unclear. In 2008, the USPSTF issued a grade D recommendation against PSA-based screening in men aged 75 years or older.² We evaluated changes in national screening rates before and after this recommendation.

According to federal regulations, the study was exempt from review by an institutional review board; patient data were deidentified and requirement for consent to our study was waived. Demographic, socioeconomic, and functional variables were collected from the 2005 and 2010 National Health Interview Survey (NHIS), which is a cross-sectional, in-person household survey continuously performed throughout each year on approximately 87 500 individuals (90% response rate).³ Multistage area probability sampling provides a representative sample of the US population. The Cancer Control Supplement, which contains questions regarding cancer screening, is included every 5 years.

For this study men aged 40 years or older without prostate cancer or other prostate-related conditions (eg, benign prostatic hyperplasia or prostatitis) who visited a physician in the prior year were included. The NHIS contains 13 questions on timing and reason for PSA testing. Men were asked “What was the main reason you had this PSA test—was it part of a routine exam, because of a problem, or some other reason?” Men who answered “because of a problem” or “other reason” were excluded from the analyses. Prostate-specific antigen screening was defined as a PSA test during a routine examination within the past year. The screening rate was estimated using sampling weights. The difference in proportion of PSA screening between 2005 and 2010 was compared using logistic regression, corrected for survey design. We conducted overall analysis and stratified by age groups. A 2-sided P value of less than .05 was considered statistically significant and the analysis was performed with Stata version 11.0 (StataCorp).

The final cohort had 5332 men from 2005 and 4640 men from 2010 (Table). The PSA screening rates were unchanged in all age groups over time (Figure). In men aged 75 years or older, PSA screening was unchanged between 2005 (43.0%; 95% CI, 38.9%-47.0%) and 2010 (43.9%; 95% CI, 39.1%-48.7%) (P = .77). In 2010, PSA screening was more common in men aged 75 years or older than in men aged 40 to 49 years (12.5%; 95% CI, 10.2%-14.7%) and 50 to 59 years (33.2%; 95% CI, 30.1%-36.3%) (P < .001 between groups) but not in men aged 60 to 74 years (51.2%; 95% CI, 48.1%-54.2%).

Large population-based studies have demonstrated PSA screening in men aged 75 years or older is inappropriately high given the limited likelihood of benefit.^4- 5 Despite the USPSTF recommendation against prostate cancer screening in men aged 75 years or older in 2008, PSA screening rates did not change. Our findings must be interpreted within the context of the study design. Data from the NHIS are deidentified and self-reported responses cannot be verified. Because self-reported PSA screening rates in the NHIS are predominantly lower compared with medical record extraction,⁶ our data are likely an underestimate. Sampling of the same individual in both years, while possible, is a rare occurrence given the sample design of the NHIS. While it is possible some men received a PSA test for reasons other than prostate cancer screening, it is likely this number is small because the NHIS questionnaire explains the test is used to detect prostate cancer and we included only men who reported a PSA as part of a routine examination. The discrepancy between the USPSTF recommendation and subsequent practice patterns may reflect lack of guideline awareness, financial incentives, or patient or physician confidence in PSA screening. Clinical practice patterns following the 2011 USPSTF recommendations should be monitored.