Background: Performance of thyroid function assays can vary significantly. To address this issue, the Centers for Disease Control and Prevention (CDC) Clinical Standardization Programs conducted an interlaboratory comparison of free thyroxine (fT4) immunoassays (IAs) and laboratory-developed tests (LDTs). This assessment aimed to determine the current performance characteristics of these assays as a first step toward measurement standardization. Thyrotropin (TSH) IAs were also evaluated. Methods: Assays measured 41 blinded individual-donor sera, including a sample from a pregnant woman (for fT4 analysis only) and three serum pools, with 11.3-32.1 pmol/L (0.881-2.49 ng/dL) fT4 and 0.337-21.6 mIU/L TSH in duplicate over 2 days. Passing-Bablok regression analysis performed pre-recalibration compared assays performance to the CDC fT4 reference measurement procedure (RMP) or TSH all-lab mean (ALM). Additionally, the impact of linear regression-based recalibration of assays to the CDC fT4 RMP or TSH ALM was estimated. Inter-assay agreement of sample classification according to the assay-specific reference interval (RI) was assessed pre- and post-recalibration. Results: A total of 21 fT4 and 17 TSH assays participated. Pre-recalibration, median biases of TSH measurements to the ALM were -1.2% [confidence interval or CI -1.8% to -0.4%], and good classification agreement among TSH assays was observed. fT4 assays all showed a negative median bias to the RMP, with higher bias among IAs (median: -20.3%, CI [-21.5% to -19.4%]) than LDTs (median: -4.5%, [CI -6.1% to -3.2%]). Of the individual-donor sera, only 21 out of 40 samples were classified uniformly by all fT4 assays, indicating poor inter-assay agreement. Post-recalibration, agreement improved to 33 out of 40 individual-donor sera correctly classified by all tested IAs and LDTs. Similar improvement in post-recalibration median percent bias was observed for fT4 IAs (median: -0.2, [CI -1.2% to 0.6%]) and LDTs (median: -0.3%, [CI -2.5% to 1.4%]). Conclusions: The comparison among fT4 assays emphasizes the need for measurement standardization to improve accuracy and comparability. This and previous studies demonstrate the possibility to develop common fT4 RIs via standardization, enabling the use of evidence-based clinical guidelines universally in patient care. Recalibration can effectively address high variability in fT4 assays, ensuring consistent diagnostic classification.

PROBLEM/CONDITION: Approximately 12 million people are living with cancer in the United States. Limited information is available on national and state assessments of health behaviors among cancer survivors. Using data from the Behavioral Risk Factor Surveillance System (BRFSS), this report provides a descriptive state-level assessment of demographic characteristics and health behaviors among cancer survivors aged ≥18 years. REPORTING PERIOD COVERED: 2009 DESCRIPTION OF SYSTEM: BRFSS is an ongoing, state-based, random-digit-dialed telephone survey of the noninstitutionalized U.S. population aged ≥18 years. BRFSS collects information on health risk behaviors and use of preventive health services related to leading causes of death and morbidity. In 2009, BRFSS added questions about previous cancer diagnoses to the core module. The 2009 BRFSS also included an optional cancer survivorship module that assessed cancer treatment history and health insurance coverage for cancer survivors. In 2009, all 50 states, the District of Columbia, Guam, Puerto Rico, and the U.S. Virgin Islands administered the core cancer survivorship questions, and 10 states administered the optional supplemental cancer survivorship module. Five states added questions on mammography and Papanicolaou (Pap) test use, eight states included questions on colorectal screening, and five states included questions on prostate cancer screening. RESULTS: An estimated 7.2% of the U.S. general population aged ≥18 years reported having received a previous cancer diagnosis (excluding nonmelanoma skin cancer). A total of 78.8% of cancer survivors were aged ≥50 years, and 39.2% had received a diagnosis of cancer >10 years previously. A total of 57.8% reported receiving an influenza vaccination during the previous year, and 48.3% reported ever receiving a pneumococcal vaccination. At the time of the interview, 6.8% of cancer survivors had no health insurance, and 12% had been denied health insurance, life insurance, or both because of their cancer diagnosis. The prevalence of cardiovascular disease was higher among male cancer survivors (23.4%) than female cancer survivors (14.3%), as was the prevalence of diabetes (19.6% and 14.7%, respectively). Overall, approximately 15.1% of cancer survivors were current cigarette smokers, 27.5% were obese, and 31.5% had not engaged in any leisure-time physical activity during the past 30 days. Demographic characteristics and health behaviors among cancer survivors varied substantially by state. INTERPRETATION: Health behaviors and preventive health care practices among cancer survivors vary by state and demographic characteristics. A large proportion of cancer survivors have comorbid conditions, currently smoke, do not participate in any leisure-time physical activity, and are obese. In addition, many are not receiving recommended preventive care, including cancer screening and influenza and pneumococcal vaccinations. PUBLIC HEALTH ACTION: Health-care providers and patients should be aware of the importance of preventive care, smoking cessation, regular physical activity, and maintaining a healthy weight for cancer survivors. The findings in this report can help public health practitioners, researchers, and comprehensive cancer control programs evaluate the effectiveness of program activities for cancer survivors, assess the needs of cancer survivors at the state level, and allocate appropriate resources to address those needs.