Background: Little is known about the medical care resources devoted to diagnosing and treating cancer-related symptoms before a definitive cancer diagnosis. Previous research using SEER-Medicare data to measure incremental costs and utilization associated with cancer started with the date of diagnosis. We hypothesized that health care use increases before diagnosis of a new primary cancer.
Methods: We used a longitudinal case-control design to estimate incremental medical care utilization rates. Cases were 121,293 persons enrolled between January 2000 and December 2008 with ≥1 primary cancers. We selected 522,839 controls randomly from among all health plan members who had no tumor registry evidence of cancer before January 2009, and we frequency matched controls to cancer cases on a 5:1 ratio by age group, sex, and having health plan eligibility in the year of diagnosis of the index cancer case. Utilization data were extracted for all cases and controls for the period 2000 to 2008 from standardized distributed data warehouses. To determine when and the extent to which patterns of medical care use change preceding a cancer diagnosis, we compute hospitalization rates, hospital days, emergency department visits, same-day surgical procedures, ambulatory medical office visits, imaging procedures, laboratory tests, and ambulatory prescription dispensings per 1000 persons per month within integrated delivery systems.
Results: One- to 3-fold increases in monthly utilization rates were observed during the 3 to 5 months before a cancer diagnosis, compared with matched noncancer control groups. This pattern was consistent for both aged and nonaged cancer patients. Aged cancer patients had higher utilization rates than nonaged cancer patients throughout the year before a cancer diagnosis.
Conclusions: The prediagnosis phase is a resource-intensive component of cancer care episodes and should be included in cost of cancer estimates. More research is needed to determine whether reliable prognostic markers can be identified as the start of a cancer episode before a pathology-based diagnosis.
*The Center for Health Research, Kaiser Permanente Northwest, Portland, OR
†The Group Health Research Institute, Seattle, WA
‡The Institute for Health Research, Kaiser Permanente Colorado, Denver, CO
§Virginia Commonwealth University, Richmond, VA
∥The Center for Health Policy and Health Services Research, Henry Ford Health System, Detroit, MI
¶The University of North Carolina, Chapel Hill, NC
Supplemental Digital Content is available for this article. Direct URL citations appear in the printed text and are provided in the HTML and PDF versions of this article on the journal's Website, www.lww-medicalcare.com.
Supported by the National Cancer Institute at the National Institutes of Health (Grant numbers R01 CA114204 and R01 CA114204-03S1 to M.C.H., RC2 CA148185 to D.P.R., and cooperative agreement number U19 CA79689 to M.C.H. and D.P.R.).
The authors declare no conflict of interest.
Reprints: Mark C. Hornbrook, PhD, The Center for Health Research, Northwest/Hawaii/Southeast, Kaiser Permanente Northwest, 3800 North Interstate Avenue, Portland, OR 97227-1110. E-mail: firstname.lastname@example.org.