Original article
Sensitivity of self-reports of cancer in a population-based prospective study: JPHC Study Cohort I

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Abstract

The sensitivity of self-reports of cancer may differ among cultures, and not many studies have dealt with it. The authors measured the sensitivity of 615 individuals from the JPHC Study Cohort I in Japan who responded to a questionnaire in 1995 and had had a cancer registry report since 1990. Sensitivity as calculated using registered cancer as the gold standard was 0.36 for any cancer, but varied considerably by site: 0.81, 0.42, 0.41, 0.26, 0.14 and 0.08 for breast, uterus, stomach, lung, colorectum and liver, respectively. This sensitivity by site relates positively with the cancer incidence/death ratio (an index of prognosis) of each site. A false name was reported in 71% of colorectal cancer cases (namely polyp) and in 51% of stomach cases (ulcer and/or polyp). In conclusion, the sensitivity of self-reports of cancer was much lower in this cohort than in the US results except for breast cancer.

Introduction

Many studies have relied upon self-reports of cancer, for example, to exclude cancer patients at the baseline in a cohort or in a case–control study, because there are usually no other methods to identify a person as being free of cancer. Thus, it is useful to determine whether self-reports of cancer are valid. There are two indicators commonly used for the validation. One is the percentage of actual cancer patients determinable by self-reports (i.e., sensitivity). The other is the percentage of self-reported cancer that is, in fact, cancer (i.e., the positive predictive value). The present study uses the first indicator.

The sensitivity of self-reports of cancer may differ with the given community or country 1, 2, 3, 4, 5, and by the time frame within a given community or country; the sensitivity was 0.33–0.61 in 1950s–70s 6, 7, 8, 9 and 0.71–0.93 in 1990s 1, 2, 3 in the US. In Japan, sensitivity is expected to increase, and telling a patient he or she has cancer used to be taboo, but is now under discussion 10, 11, 12.

The main purpose of the present study was to measure the sensitivity of self-reports of cancer in a population-based prospective study, which to our knowledge is for the first time outside North America or Europe. An additional aim was to analyze determinants that might affect the sensitivity; these include cancer site, gender, study area, smoking status, alcohol use, time between cancer diagnosis and the questionnaire, and years of formal education.

Section snippets

JPHC Study Cohort I

The present study was a part of the Japan Public Health Center-based prospective Study on cancer and cardiovascular diseases (the JPHC Study) Cohort I [13]. The subjects were drawn from the general public, either with or without disease, in four local areas: Ninohe Public Health Center (PHC) area in Iwate (Area A), Yokote PHC area in Akita (Area B), Saku PHC area in Nagano (Area C), and Ishikawa PHC area in Okinawa (Area D). All residents born from 1930 through 1949 were enrolled as of January

Results

Of 615 subjects, 221 self-reported their cancer in the questionnaire, for a sensitivity of 0.36 (95% CI 0.32–0.40) (Table 1). Sensitivity varied considerably by cancer site, with the values of 0.81, 0.42, 0.41, 0.26, 0.14 and 0.08 for breast, uterus, stomach, lung, colorectum and liver, respectively.

As to the cancer sites, sensitivity varied less by sex (Table 1), area (Table 2), smoking status, alcohol use, time between diagnosis and the questionnaire survey, and education (Table 3). The crude

Discussion

Sensitivity of self-reports of any cancer was 0.36 in the present study. This value is similar to the proportion of inpatients who were notified of their cancer in a hospital for the elderly [19]. This level is much lower than the 0.71 and 0.93 values from recent US studies 1, 2. Sensitivity was reported to be slightly lower in the age group of 70 years or older in a study [2]. However, this relationship did not explain the relatively lower sensitivity in the present study, because our

Acknowledgements

We express our appreciation to Mr. Michael Fahey, who critically reviewed interpretation and expression of the results; Ms. Yuko Iwatare, who was in charge of cancer registration; and other colleagues who have supported this project.

This work was supported by grants-in-aid for Cancer Research and for the Second-Term Comprehensive Ten-Year Strategy for Cancer Control from the Ministry of Heath and Welfare of Japan. Ako Yoshinaga is an Awardee of a Research Resident Fellowship from the Foundation

References (31)

  • O.O. Thomsen et al.

    What do gastroenterologists in Europe tell cancer patients?

    Lancet

    (1993)
  • A. Paganini-Hill et al.

    Accuracy of recall of hip fracture, heart attack, and cancera comparison of postal survey data and medical records

    Am J Epidemiol

    (1993)
  • M.M. Bergmann et al.

    Validity of self-reported cancers in a prospective cohort study in comparison with data from state cancer registries

    Am J Epidemiol

    (1998)
  • I. Kato et al.

    Comparison of active and cancer registry-based follow-up for breast cancer in a prospective cohort study

    Am J Epidemiol

    (1999)
  • L.W. Chambers et al.

    Underreporting of cancer in medical surveysa source of systematic error in cancer research

    Am J Epidemiol

    (1976)
  • C.T. Schrijvers et al.

    Validation of cancer prevalence data from a postal survey by comparison with cancer registry records

    Am J Epidemiol

    (1994)
  • S.D. Harlow et al.

    Agreement between questionnaire data and medical records. The evidence for accuracy of recall

    Am J Epidemiol

    (1989)
  • D.E. Krueger

    Measurement of prevalence of chronic disease by household interviews and clinical evaluations

    Am J Public Health

    (1957)
  • National Center for Health Statistics. Health interview responses compared with medical records. Vital and health...
  • Madow MG. Net differences in interview data on chronic conditions and information derived from medical records. Vital...
  • Bioethics Council of the Japan Medical Association. [A report on “informed consent.” Part 1.] Nihon Iji Shinpo...
  • Bioethics Council of the Japan Medical Association. [A report on “informed consent.” Part 2.] Nihon Iji Shinpo...
  • Bioethics Council of the Japan Medical Association. [A report on “informed consent.” Part 3.] Nihon Iji Shinpo...
  • S. Tsugane et al.

    Alcohol consumption and all-cause and cancer mortality among middle-aged Japanese menseven-year follow-up of the JPHC Study Cohort I

    Am J Epidemiol

    (1999)
  • S. Tsugane et al.

    Cross-sectional epidemiologic study for assessing cancer risks at the population level. I. Study design and participation rate

    J Epidemiol

    (1992)
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