Affiliations of authors: HealthStat, Princeton, NJ (GLY); Institute for Clinical Evaluative Sciences, Toronto, Ontario, Canada (TAS); Dean and Betty Gallo Prostate Cancer Center, Cancer Institute of New Jersey, New Brunswick, NJ (GLY, SLY).
Correspondence to: Siu-Long Yao, MD, Dean and Betty Gallo Prostate Cancer Center, Cancer Institute of New Jersey, Rm. 204, 195 Little Albany St., New Brunswick, NJ 089011914 (e-mail: syao{at}aya.yale.edu)
![]() |
ABSTRACT |
---|
![]() ![]() ![]() ![]() |
---|
Despite controversy regarding the efficacy of PSA screening, there has been general agreement that men aged 75 years or older (i.e., elderly men) should not be screened (3,512). The decision to not screen is primarily a consequence of the long natural history of untreated localized prostate cancer, the impact of competing causes of death, and the recognition that life expectancy without treatment is nearly identical to survival following definitive therapies in men aged 70 years or older (9,1215).
However, despite the consensus that testing in the elderly has little benefit, there has been some circumstantial information that suggests that there is a high prevalence of screening among elderly men (16,17). Whether the putatively high rate of screening is a consequence of patient demands or physician suggestions has been unclear. In addition, there are few data regarding whether discussion of the risks and benefits of PSA screening took place before testing, as most guidelines recommend. We undertook this study to determine 1) rates of PSA screening in the elderly, 2) proportions of PSA screenings initiated by physicians, 3) proportions of PSA screenings preceded by discussion of risks and benefits, and 4) patient factors associated with PSA screening.
The National Health Interview Survey (NHIS) is a continuing, population-based, stratified, multistage health survey conducted by the U.S. Census Bureau (18). NHIS files from 2000 were used to obtain data on PSA use and the characteristics of the study population. All information was based on in-person, interview-directed, self-reports.
Key factors considered in this study were identified from previous literature (1921) and are summarized in the "Appendix." To determine the reasons for testing, patients were asked, "What was the main reason you had this PSA test?" The primary purpose of PSA testing was considered screening if the test was part of a routine physical exam or if it was explicitly stated that it was for screening. Men who received a PSA test for reasons other than screening were excluded from the numerator but included in the screening rate denominator. Specific questions used to ascertain the context of screening included "Who first suggested the PSA test? You, your doctor, or someone else?" and "Did the doctor discuss the advantages and disadvantages of the most recent PSA test with you before doing it?"
Ages reported in this study refer to age at screening. To properly categorize individuals who had a PSA screening test after age 75 years, we used a cut point of age 76 years at the time of the interview because the survey asked whether screening had occurred during the preceding 12 months. The same methodology was applied to all age groups in estimating screening rates. We used the STATA statistical software package (22,23), which incorporated individual survey weights and accounted for the multistage stratified design, to obtain variance estimates. Multivariable logistic regression was used to examine the effect of various factors on PSA testing. All statistical tests were two-tailed at an alpha level of .05. Informed consent and Institutional Review Board approval were obtained by the National Center for Health Statistics.
The 2000 NHIS sample consisted of 100 618 individuals from approximately 46 000 households. Among the individuals who responded to the NHIS survey (overall response rate = 88.9%), of the 7889 men without existing prostate cancer who were eligible for our PSA screening study, 762 were aged 76 years or older at the time of the interview. The PSA screening rate was 24.0% (95% CI = 19.1% to 28.9%) among men aged 80 years or older, 38.8% (95% CI = 33.7% to 43.9%) among men aged 7579 years, 40.0% (95% CI = 37.0% to 43.0%) among men aged 6574 years, 31.2% (95% CI = 28.5% to 34.0%) among men aged 5564 years, and 17.8% (95% CI = 15.9% to 19.7%) among men aged 4554 years. Approximately 32.5% (95% CI = 28.8% to 36.1%) of men aged 75 years or older (1.47 million men) had a PSA screening test during the year 2000. The characteristics of men aged 75 years or older, according to screening status, are summarized in Table 1.
|
The effect of various factors on the use of PSA screening is summarized in Table 2. After adjusting for the variables listed in the "Appendix," only fecal occult blood screening was positively associated with PSA screening in both young and elderly men. Receiving an influenza vaccination was positively associated with PSA screening among men aged younger than 75 years. A similar observation was found among elderly men, although the association between influenza vaccination and PSA screening did not reach statistical significance. Known risk factors for prostate cancer such as race/ethnicity and family history were associated with PSA screening among men aged younger than 75 years but not among elderly men. Lacking medical insurance and being unable to afford medical care are often associated with lower use of preventive care (26) and were found to be inversely associated with PSA screening among men aged younger than 75 years.
|
In considering the results of our study, high rates of screening in the elderly were perhaps discernible in some previous studies (16,17,2426). The rates of screening in these studies (16,17,24,25) were generally higher than in our study, possibly because these studies were not able to determine the reasons for PSA testing. In our study, for example, we found that approximately one-third of PSA tests were not used for screening purposes.
We found that 88% of elderly men who received screening reported that their physicians first suggested screening. These results are consistent with, but perhaps more remarkable than, previous studies (24,2730). On the one hand, it seems reasonable that men would defer to their physicians after being informed by the physician of the controversy. On the other hand, however, it is somewhat surprising that so many physicians would suggest screening (or be perceived as suggesting screening) in elderly men when the benefits have not even been established among younger men.
Use of preventive care, such as fecal occult blood screening, was the most important predictor of PSA screening use. Clinical factors, such as comorbidity and functional status, did not appear to play important roles in the decision to receive screening among elderly men. Additionally, known risk factors for prostate cancer, such as family history and race/ethnicity, were not associated with PSA screening among elderly men.
Our database presented us with a unique opportunity to examine, in detail, factors associated with the decision to screen (including physician suggestion and rates of discussion) and, by accumulating data throughout the United States, provided estimates of screening rates that are potentially more accurate than those in previous studies (16,17,24,25). However, some limitations of this study should be considered in the interpretation of the results. For example, surveys are subject to nonresponse, self-reporting errors, recall bias, or errors of misinterpretation. In our study, those who had never heard of, or did not know about, PSA screening were assumed to have never had a PSA test. However, previous studies demonstrated that some patients were unaware that PSA testing had been performed on their behalf (31,32). Under such circumstances, our results would underestimate the rate of testing. The effect of recall bias on our estimates of PSA screening may be clearer for whether screening was performed than for questions regarding who suggested screening, whether the risks and benefits were discussed, and the purpose of testing. From a practical perspective, however, what the patient recalls is probably what is most important. For example, if a patient cannot recall a discussion concerning risks and benefits, then it is likely that the discussion was ineffective and did not fulfill its primary objective.
Elderly men as defined in this study (i.e., men aged 76 years or older at interview) had a life expectancy of less than 10 years (33). Nonetheless, these elderly men accounted for approximately 1.47 million U.S. men who had PSA screening in 2000. Screening a population that is unlikely to benefit or act on the test results has several important implications. First, with the healthcare system economically strained, the considerable resources expended for screening could be applied elsewhere. Second, if medical benefit for elderly men is uncertain, the potential harms of screening this population (e.g., resulting morbidity from unnecessary treatment) may be important (34). Third, for men who choose observation after receiving a diagnosis of prostate cancer, the impact of anxiety on the patient should not be underestimated (35).
Ultimately, decisions regarding the appropriateness of PSA screening in elderly men and the allocation of health care resources will have to be made by patients, physicians, and society working together. Until such decisions can be made, recognizing and understanding the reasons for the high rates of PSA screening in elderly men may provide insights into how patients (and physicians) use, interpret, and apply medical data. Such information may be critically important for the development of strategies designed to increase understanding of the risks and benefits of PSA screening in elderly men.
|
![]() |
NOTES |
---|
![]() ![]() ![]() ![]() |
---|
![]() |
REFERENCES |
---|
![]() ![]() ![]() ![]() |
---|
1 Jemal A, Thomas A, Murray T, Thun M. Cancer statistics, 2002. CA Cancer J Clin 2002;52:2347.
2 Prostate-specific antigen (PSA) best practice policy. American Urological Association (AUA). Oncology (Huntingt) 2000;14:26772, 2778, 280 passim.[Medline]
3 Smith RA, Cokkinides V, von Eschenbach AC, Levin B, Cohen C, Runowicz CD, et al. American Cancer Society guidelines for the early detection of cancer. CA Cancer J Clin 2002;52:822.
4 Fowler FJ Jr, Bin L, Collins MM, Roberts RG, Oesterling JE, Wasson JH, et al. Prostate cancer screening and beliefs about treatment efficacy: a national survey of primary care physicians and urologists. Am J Med 1998;104:52632.[CrossRef][ISI][Medline]
5 Ferrini R, Woolf SH. American College of Preventive Medicine practice policy. Screening for prostate cancer in American men. Am J Prev Med 1998;15:814.[CrossRef][ISI][Medline]
6 Poteat HT, Chen P, Loughlin KR, Winkelman JW, Allada R, Maluf N, et al. Appropriateness of prostate-specific antigen testing. Am J Clin Pathol 2000;113:4218.[CrossRef][ISI][Medline]
7 Richter F, Dudley AW Jr, Irwin RJ Jr, Sadeghi-Nejad H. Are we ordering too many PSA tests? Prostate cancer diagnosis and PSA screening patterns for a single Veterans Affairs Medical Center. J Cancer Educ 2001;16:3841.[ISI][Medline]
8 Carter HB, Landis PK, Metter EJ, Fleisher LA, Pearson JD. Prostate-specific antigen testing of older men. J Natl Cancer Inst 1999;91:17337.
9 Albertsen PC, Hanley JA, Gleason DF, Barry MJ. Competing risk analysis of men aged 55 to 74 years at diagnosis managed conservatively for clinically localized prostate cancer. JAMA 1998;280:97580.
10 Coley CM, Barry MJ, Fleming C, Fahs MC, Mulley AG. Early detection of prostate can-cer. Part II: Estimating the risks, benefits, and costs. American College of Physicians. Ann Intern Med 1997;126:46879.
11 Krahn MD, Mahoney JE, Eckman MH, Trachtenberg J, Pauker SG, Detsky AS. Screening for prostate cancer. A decision analytic view. JAMA 1994;272:77380.[Abstract]
12 Fleming C, Wasson JH, Albertsen PC, Barry MJ, Wennberg JE. A decision analysis of alternative treatment strategies for clinically localized prostate cancer. Prostate Patient Outcomes Research Team. JAMA 1993;269:26508.[Abstract]
13 Johansson JE, Holmberg L, Johansson S, Bergstrom R, Adami HO. Fifteen-year survival in prostate cancer. A prospective, population-based study in Sweden [published erratum appears in JAMA 1997;278:206]. JAMA 1997;277:46771.[Abstract]
14 Johansson JE, Adami HO, Andersson SO, Bergstrom R, Holmberg L, Krusenmo UB. High 10-year survival rate in patients with early, untreated prostatic cancer. JAMA 1992;267:21916.[Abstract]
15 Chodak GW, Thisted RA, Gerber GS, Johansson JE, Adolfsson J, Jones GW, et al. Results of conservative management of clinically localized prostate cancer. N Engl J Med 1994;330:2428.
16 Merrill RM. Demographics and health-related factors of men receiving prostate-specific antigen screening in Utah. Prev Med 2001;33:64652.[CrossRef][ISI][Medline]
17 Etzioni R, Berry KM, Legler JM, Shaw P. Prostate-specific antigen testing in black and white men: an analysis of Medicare claims from 19911998. Urology 2002;59:2515.[CrossRef][ISI][Medline]
18 National Center for Health Statistics. Data file documentation, National Health Interview Survey, 2000 [machine readable data file and documentation]. Hyattsville (MD): National Center for Health Statistics; 2001. Available at: http://www.cdc.gov/nchs/nhis.htm#2000_ NHIS. [Last accessed: October 24, 2003.]
19 Hiatt RA, Klabunde C, Breen N, Swan J, Ballard-Barbash R. Cancer screening practices from National Health Interview Surveys: past, present, and future. J Natl Cancer Inst 2002;94:183746.
20 Breen N, Wagener DK, Brown ML, Davis WW, Ballard-Barbash R. Progress in cancer screening over a decade: results of cancer screening from the 1987, 1992, and 1998 National Health Interview Surveys. J Natl Cancer Inst 2001;93:170413.
21 Brown ML, Potosky AL, Thompson GB, Kessler LG. The knowledge and use of screening tests for colorectal and prostate cancer: data from the 1987 National Health Interview Survey. Prev Med 1990;19:56274.[ISI][Medline]
22 Sarndal C, Swensson B, Wretman JH. Model assisted survey sampling. 4th ed. New York (NY): Springer Verlag; 1992.
23 Stata software, version 7.0. College Station (TX): Stata Corporation; 2001.
24 Cowen ME, Kattan MW, Miles BJ. A national survey of attitudes regarding participation in prostate carcinoma testing. Cancer 1996;78:19527.[CrossRef][ISI][Medline]
25 Jacobsen SJ, Katusic SK, Bergstralh EJ, Oesterling JE, Ohrt D, Klee GG, et al. Incidence of prostate cancer diagnosis in the eras before and after serum prostate-specific antigen testing. JAMA 1995;274:14459.[Abstract]
26 Swan J, Breen N, Coates RJ, Rimer BK, Lee NC. Progress in cancer screening practices in the United States: results from the 2000 National Health Interview Survey. Cancer 2003;97:152840.[CrossRef][ISI][Medline]
27 Perkins JJ, Sanson-Fisher RW, Clarke SJ, Youman P. An exploration of screening practices for prostate cancer and the associated community expenditure. Br J Urol 1998;82:5249.[CrossRef][ISI][Medline]
28 Slevin TJ, Donnelly N, Clarkson JP, English DR, Ward JE. Prostate cancer testing: behaviour, motivation and attitudes among Western Australian men. Med J Aust 1999;171:1858.[ISI][Medline]
29 Carter F, Graham E, Pal N, Gonzalez E, Roetzheim R. Prostate cancer screening in primary care. South Med J 1999;92:3004.[ISI][Medline]
30 Steele CB, Miller DS, Maylahn C, Uhler RJ, Baker CT. Knowledge, attitudes, and screening practices among older men regarding prostate cancer. Am J Public Health 2000;90:1595600.
31 Federman DG, Goyal S, Kamina A, Peduzzi P, Concato J. Informed consent for PSA screening: does it happen? Eff Clin Pract 1999;2:1527.[Medline]
32 Diefenbach PN, Ganz PA, Pawlow AJ, Guthrie D. Screening by the prostate-specific antigen test: what do the patients know? J Cancer Educ 1996;11:3944.[Medline]
33 Minino AM, Arias E, Kochanek KD, Murphy SL, Smith BL. Deaths: final data for 2000. Natl Vital Stat Rep 2002;50:1119.[Medline]
34 Yao SL, Lu-Yao G. Understanding and appreciating overdiagnosis in the PSA era. J Natl Cancer Inst 2002;94:95860.
35 Lofters A, Juffs HG, Pond GR, Tannock IF. "PSA-itis": knowledge of serum prostate specific antigen and other causes of anxiety in men with metastatic prostate cancer. J Urol 2002;168:251620.[CrossRef][ISI][Medline]
36 Charlson ME, Pompei P, Ales KL, MacKenzie CR. A new method of classifying prognostic comorbidity in longitudinal studies: development and validation. J Chronic Dis 1987;40:37383.[ISI][Medline]
37 U.S. Census Bureau. Current population survey: poverty 2000. Washington (DC): U.S. Department of Commerce; 2001. Available at: http://www.census.gov/hhes/poverty/povdef.html. [Last accessed: October 24, 2003.]
Manuscript received May 1, 2003; revised September 4, 2003; accepted September 22, 2003.
This article has been cited by other articles in HighWire Press-hosted journals:
![]() |
||||
|
Oxford University Press Privacy Policy and Legal Statement |