Reliability of Family Proxy Data for Studies of Malignant Mesothelioma: Results from the ATSDR Pilot Surveillance

Our plain-English summary of Reliability of Family Proxy Data for Studies of Malignant Mesothelioma: Results from the ATSDR Pilot Surveillance, by N. Melnikova, J. Wu, W. Kaye, et al (ISRN Oncology, 2013).

The study

• Authors: N. Melnikova, J. Wu, W. Kaye, M. Orr
• Journal: ISRN Oncology
• Published: 2013;2013:325409
• Cited by: 1 article, as counted by NIH iCite
• Read it: PubMed · Publisher · Free full text

Abstract

Objective. To evaluate the validity of proxy interviews in obtaining information on persons with rapidly fatal diseases such as malignant mesothelioma (MM). Methods. Persons with MM diagnosed in 2002 through 2005 in New York and New Jersey and 1997-2004 in Wisconsin were eligible for inclusion in the project. Persons with MM and their family member proxy were interviewed using the same questionnaire designed by ATSDR to collect information on potential direct or indirect occupational and environmental exposure to asbestos, genetic, and health related malignancy predisposition, and exposure to tobacco products. Descriptive statistics and the McNemar/Durkalski test were used to analyze 33 matched pairs. Results. The overall study confirmed a generally high ability of proxies to give interviews of comparable quality and completeness when asked dichotomous questions. The reliability of information collected from proxies varied by topic and family relationship. Conclusions. Family proxy interviews, using dichotomous responses, can serve as an acceptable source of information about health and exposure-related risk factors for MM.

In plain English

In an Agency for Toxic Substances and Disease Registry (ATSDR) pilot project, the authors compared answers from people with malignant mesothelioma with answers from a family member each patient chose as a proxy. Patients diagnosed in 2002 through 2005 in New York and New Jersey, or 1997 to 2004 in Wisconsin, and their proxies answered the same telephone questionnaire. It asked about direct or indirect asbestos exposure at work and in the environment, medical and family history, and smoking. The analysis covered 33 pairs and 73 yes-or-no questions. About half the proxies were spouses. Agreement by topic ranged from 85.3% (family medical history) to 88.9% (the patient's medical history). Disagreement was statistically significant only for smoking history (chi-square 5.57, P = 0.02), and within that only for spouses. The authors said the large number of spouses contributed to this. They named the small number of pairs as the biggest limitation. The authors concluded that family proxy interviews using yes-or-no questions can be an acceptable source of information on risk factors for mesothelioma.

We wrote this plain-English summary from the full article with the help of AI, and a second AI model checked each sentence against the article. It is not the authors' wording; the abstract and the article are their own account.

What the study did and found

• Design: Comparison of matched interviews (patient versus family proxy) within a pilot surveillance project, analyzed with descriptive statistics and an adjusted McNemar (McNemar/Durkalski) test
• Who was studied: 33 pairs, each made up of a person with malignant mesothelioma and a family member proxy. The patients were diagnosed in 2002 through 2005 in New York and New Jersey and in 1997 to 2004 in Wisconsin. There were 8 pairs from New Jersey, 10 from New York and 15 from Wisconsin. Proxies were 17 spouses (51.4%), 6 children, 5 siblings and 5 other/parents. Patients were mostly white, non-Hispanic, married men.
• Exposure: Self- or proxy-reported potential direct or indirect occupational and environmental asbestos exposure, assessed with an adapted EPA list of jobs and activities. The questionnaire also covered genetic and health-related predisposition to cancer and tobacco use. No fiber types were named.
• Main results:
  • Across all proxies, agreement was highest for questions on the patient's medical history: 704 paired responses agreed (88.9%).
  • Across all proxies, agreement was lowest for family medical history questions: 366 paired responses agreed (85.3%).
  • Spouses had the highest agreement on the patient's exposure questions (89.8%).
  • Parents had the highest agreement on family exposure questions (95.7%).
  • Patient medical and family medical questions had the most missing or unknown answers (3.8% and 4.2%).
  • The test found no statistically significant difference between patient and proxy answers for any relationship or topic, except smoking history.
  • Smoking history showed statistically significant disagreement overall (chi-square 5.57, P = 0.02). Within that, the disagreement was significant only for spouses (chi-square 5.91, P = 0.02).
  • The authors said the larger number of spouses in the group contributed to the statistical significance for smoking history.
  • The authors said spouses' percent disagreement on smoking was not much higher than that of the other groups of proxies.
• The authors' conclusion: The authors concluded that family proxy interviews using yes-or-no questions can be an acceptable source of information on health and exposure-related risk factors for malignant mesothelioma. They said reliability was generally high but varied by topic and family relationship.
• Limitations the authors state:
  • The small number of paired interviews (33) was the biggest limitation. With more pairs, siblings and others with borderline P values might show significant differences.
  • The sample may be biased: patients chose the family member they thought would give the best information.
  • Participating patients may have survived longer than those who could not take part.
  • Pending litigation and communication between patient and proxy about the interview may have affected accuracy.
  • More detailed, multilevel answers were not analyzed because they did not agree well or were hard to compare.

Topics

Medical terms in this study, explained in our Lexicon: Malignant Mesothelioma, ATSDR, Environmental Exposure.

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• Mesothelioma trends in the United States: an update based on Surveillance, Epidemiology, and End Results Program data for 1973 through 2003 — B. Price, A. Ware (2004)
• Compensation of pleural mesothelioma in France: data from the French National Mesothelioma Surveillance Programme — S. Chamming's, B. Clin, et al. (2013)
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• Re: "Mesothelioma trends in the United States: an update based on surveillance, epidemiology, and end results program data for 1973 through 2003" — J.H. Lange (2004)

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