Measuring Comorbidity in Patients With Head and Neck Cancer

Authors

  • Stephen F. Hall MSc, MD, FRCSC,

    Corresponding author
    1. Department of Otolaryngology, Department of Oncology and the Radiation Oncology Research Unit (Cancercare and Epidemiology Division of the Queen's University Cancer Research Institute, Queen's University, Kingston, Ontario, Canada
    • 144 Brock St, Kingston, Ontario, Canada, K7L 5G2
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  • Paula A. Rochon MD, MPH, FRCPC,

    1. Kunin-Lunenfeld Applied Research Unit, Toronto, Ontario, Canada
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  • David L. Streiner PhD, C Psych,

    1. Kunin-Lunenfeld Applied Research Unit, Toronto, Ontario, Canada
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  • Lawrence F. Paszat BA, MD, MS, FRCRC,

    1. Institute of Clinical Evaluative Sciences, Toronto, Ontario, Canada.
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  • Patti A. Groome PhD,

    1. Department of Otolaryngology, Department of Oncology and the Radiation Oncology Research Unit (Cancercare and Epidemiology Division of the Queen's University Cancer Research Institute, Queen's University, Kingston, Ontario, Canada
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  • Susan L. Rohland

    1. Department of Otolaryngology, Department of Oncology and the Radiation Oncology Research Unit (Cancercare and Epidemiology Division of the Queen's University Cancer Research Institute, Queen's University, Kingston, Ontario, Canada
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Abstract

Background Comorbidities are diseases or conditions that coexist with a disease of interest. The importance of comorbidities is that they can alter treatment decisions, change resource utilization, and confound the results of survival analysis.

Objective The objective of this study was to determine the best comorbidity index to use in survival analysis of patients with squamous cell carcinoma of the head and neck.

Method Four validated indexes, with very different methodologies (i.e., the Charlson Index, the Cumulative Illness Rating Scale, the Kaplan-Feinstein Classification, the Index of Co-existent Disease), were tested using data from 379 unselected consecutive patients with complete 3-year follow-up from the Kingston Regional Cancer Center. Kaplan-Meier analysis and Cox Proportional Hazards Regression were used to stratify patients into three levels of increasing severity of comorbidity for each index. The Proportion of Variance Explained and Receiver Operating Characteristics curves were used to compare the performance of the indexes.

Conclusion The Kaplan-Feinstein Classification was the most successful in stratifying patients in this population.

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