Assessment of causes of death in a prostate cancer screening trial

Abstract

Accurate assessment of the causes of death is crucial for a conclusive evaluation of the ongoing prostate cancer screening trials. Here, we report the validity of the official causes of death as compared with an independent expert review in the Finnish prostate cancer screening trial. Because nearly 80,000 men were involved, death-cause evaluation was restricted to men diagnosed for prostate cancer. Medical charts were retrieved and the cause of death was assigned by an expert review panel for all deaths among men with prostate cancer during the study period, 1996-2003. The panel decision was compared with both death certificates and the official causes of death as assigned by Statistics Finland. Of a total of 315 deaths, the review panel attributed 127 (41%) to prostate cancer and 184 (59%) to other causes, the corresponding figures in death certificates being 124 (40%) and 187 (60%). Four cases were excluded because of insufficient information. The death-certificate data were in agreement with the panel's assessment in 305 out of 311 cases (overall agreement 97.7%, j 5 0.95). The overall agreement between the official causes of death and the panel's decision was 97.4% (304/311, j 5 0.95). The sensitivity of the certificates in identifying prostate cancer deaths was 96.1% (panel as golden standard). Correspondingly, specificity was 98.9%. The official causes of death thus provide an accurate means for evaluating disease-specific mortality in a large population-based prostatecancer screening trial in Finland. ' 2007 Wiley-Liss, Inc.Key words: prostate cancer; prostate-specific antigen; mass screening; cause of death; mortality; randomized trials Prostate cancer mortality is declining in some parts of the world, e.g., in the United States.1 Widespread debate has prevailed as to the extent to which the decrease may be a consequence of prostate-specific antigen (PSA)-based screening. The only valid means of settling the issue is through large randomized screening trials. Such trials are currently under way in both the United States (Prostate, Lung, Colorectal and Ovary screening trial, PLCO) and Europe (European Randomized Study of Prostate Cancer Screening, ERSPC), and the first mortality results are expected within a few years.2 Nevertheless the value of these ongoing trials has been questioned by suggesting that it would be almost impossible to demonstrate (or rule out) the value of PSA screening on account of possible misdiagnosis of the cause of death in elderly men with multiple comorbidities.3 Accurate assessment of the underlying cause of death is thus crucial for a conclusive evaluation of the possible benefits of prostate cancer screening. For several chronic conditions, a panel of experts has been regarded as the preferred strategy to establish cause-specific mortality for research purposes. [4][5][6] However, the use of death certificates has also been advocated to avoid labor-intensive and costly death reviews in large epidemiological studies. 7The Finnish prostate cancer screening trial is a part of ...

Do we really know the cause of death of the very old? Comparison between official mortality statistics and cohort study classification

“…Several studies of the validity of death certificate diagnosis have been published [4][5][6][7][8][9][10][11][12][13][14][15]. Most have focused on a specific disease (mainly cardiac disease or cancer, but also asthma, diabetes, etc.…”

Components of the metabolic syndrome and risk of prostate cancer: the HUNT 2 cohort, Norway

“…In many countries, the underlying cause of death is assigned by the national cause of death registries on the basis of physician-completed death certificates, which are known to be unreliable, particularly for long-latency diseases in the elderly such as prostate cancer [38][39][40]. In Norway, however, the unique 11-digit identity number allows close collaboration between the Cancer Registry and the Cause of Death Registry, such that the underlying cause of death is assigned on the basis of information transferred from the Cancer Registry (year of diagnosis, histology, basis for and certainty of the diagnosis, and extent of disease at time of diagnosis), as well as death certificates, autopsy reports, and queries to physicians [41].…”

Lower urinary tract symptoms and risk of prostate cancer: The HUNT 2 Cohort, Norway

“…Briefly, information was collected on a range of lifestyle and health-related factors, including measures of physical activity, smoking, alcohol consumption, marital status and education. In addition, participants completed a self-administered questionnaire at home (for return in a pre-stamped envelope) that included the validated International Prostate Symptom Score (IPSS), 17 which was used to rate LUTS severity as no (0), mild (1-7), moderate (8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19) or severe (20)(21)(22)(23)(24)(25)(26)(27)(28)(29)(30)(31)(32)(33)(34)(35) LUTS. The population in Nord-Trønde-lag County (127,000 residents) is stable, with a net out-migration of 0.3% per year (1996)(1997)(1998)(1999)(2000), and is ethnically homogenous (less than 3% non-Caucasian).…”

“…In many countries, the underlying cause of death is assigned by national cause of death registries on the basis of physician-completed death certificates, which are known to be unreliable, particularly for long-latency diseases in the elderly such as prostate cancer. [18][19][20] In Norway, however, the unique 11-digit identity number allows close collaboration between the Cancer Registry and the Cause of Death Registry, such that underlying cause of death is assigned on the basis of information transferred from the Cancer Registry (year of diagnosis, histology, basis for and certainty of the diagnosis and extent of disease at time of diagnosis), as well as death certificates, autopsy reports and queries to physicians. 21 In a validation exercise there was less than a 1% discrepancy between an underlying causes of death being assigned as prostate cancer from the official mortality statistics and, based on the same information, the underlying causes of death assigned by independent expert review.…”