Changing patterns of use of osteoporosis medications in the years after launch: implications for comparative effectiveness research.

PURPOSE: Newly marketed medications may be used selectively in patients with more severe disease. Changes in patterns of use following a drug's introduction to the market can greatly influence results from non-experimental comparative effectiveness research. We sought to explore this issue by characterizing trends in oral and injectable prescription drug claims for the prevention and treatment of osteoporosis. METHODS: We examined a post-menopausal population of women age 55 years and older in the Truven Health Analytics MarketScan® Databases. We used propensity score (PS) methods to describe how predictors of new users of oral and injectable osteoporosis medications change over time. RESULTS: We found that injectable osteoporosis medications tended to be used more selectively in the higher risk patients shortly after launch. Over time, they appeared to be used increasingly in lower risk patients. CONCLUSION: If disease severity is incompletely captured in the data, comparative effectiveness of novel osteoporosis medications may be difficult to accurately estimate, particularly when medications are new to market.

Validation of the Osteoporosis-Specific Morisky Medication Adherence Scale in long-term users of bisphosphonates.

PURPOSE: To examine the psychometric properties and validity of the 8-item Osteoporosis-Specific Morisky Medication Adherence Scale (OS-MMAS-8) in postmenopausal women prescribed bisphosphonates (BPs) for at least 15 months. METHODS: A random sample of women aged ≥55 years with osteoporosis prescribed daily or weekly BPs was identified. Pharmacy fill data were extracted to calculate the medication possession ratio (MPR). Eligible women were stratified by low (<0.50), medium (0.50-0.79), or high (≥0.80) MPR, with the a priori goal of recruiting 133 participants in each group. OS-MMAS-8 scores can range from 0 to 8 and were categorized as low (<6), medium (6 to <8), and high (8) adherence. Internal consistency reliability (Cronbach's alpha), test-retest reliability [intraclass correlation coefficients (ICCs)] and convergent validity (correlating OS-MMAS-8 with MPR and other self-reported measures) were assessed. RESULTS: A total of 400 women out of 449 respondents reported that they were still taking their BPs at the time of the survey and completed OS-MMAS-8. Overall, 38.5, 34.3, and 27.3% of participants had low, medium, and high OS-MMAS-8 scores, respectively. The mean (SD) MPRs according to OS-MMAS-8 scores (<6, 6 to <8 and 8) were 56.9 (22.6), 69.0 (24.9), and 76.7 (26.4), respectively. The correlation between OS-MMAS-8 and MPR was 0.36; p < 0.0001. Cronbach's alpha was 0.74, and the ICC was 0.83 (95% CI 0.76-0.88). CONCLUSIONS: OS-MMAS-8 has acceptable psychometric properties for assessing medication adherence in postmenopausal women prescribed therapy for osteoporosis. Additional studies are needed to investigate the psychometric properties of OS-MMAS-8 in other settings and populations.

Prevalence and incidence of comorbidities in elderly women with ovarian cancer.

OBJECTIVE: Studies suggest comorbidity plays an important role in ovarian cancer. We characterized the epidemiology of comorbid conditions in elderly U.S. women with ovarian cancer. METHODS: Women with ovarian cancer age ≥66 years, and matched cancer-free women, were identified using the National Cancer Institute's Surveillance, Epidemiology, and End Results registry linked to Medicare claims. Prevalence before diagnosis/index date and 3- and 12-month incidence rates (per 1000 person-years) after diagnosis/index date were estimated for 34 chronic and acute conditions across a broad range of diagnostic categories. RESULTS: There were 5087 each of women with ovarian cancer and cancer-free women. The prevalence of most conditions was similar between cancer and cancer-free patients, but exceptions included hypertension (51.8% and 43.5%, respectively), osteoarthritis (13.4% and 17.3%, respectively), and cerebrovascular disease (8.0% and 9.8%, respectively). In contrast, 3- and 12-month incidence rates (per 1000 person years) of most conditions were significantly higher in cancer than in cancer-free patients: hypertension (177.3 and 47.4, respectively); thromboembolic event (145.3 and 5.5, respectively); congestive heart failure (113.3 and 28.6, respectively); infection (664.4 and 55.2, respectively); and anemia (408.3 and 33.1, respectively) at 12 months. CONCLUSIONS: Comorbidities were common among elderly women. After cancer diagnosis, women with ovarian cancer had a much higher incidence of comorbidities than cancer-free women. The high incidence of some of these comorbidities may be related to the cancer or its treatment, but others may have been prevalent but undiagnosed until the cancer diagnosis. The presence of comorbidities may affect treatment decisions.

Misclassification of incident conditions using claims data: impact of varying the period used to exclude pre-existing disease.

BACKGROUND: Estimating the incidence of medical conditions using claims data often requires constructing a prevalence period that predates an event of interest, for instance the diagnosis of cancer, to exclude those with pre-existing conditions from the incidence risk set. Those conditions missed during the prevalence period may be misclassified as incident conditions (false positives) after the event of interest.Using Medicare claims, we examined the impact of selecting shorter versus longer prevalence periods on the incidence and misclassification of 12 relatively common conditions in older persons. METHODS: The source of data for this study was the National Cancer Institute's Surveillance, Epidemiology, and End Results cancer registry linked to Medicare claims. Two cohorts of women were included: 33,731 diagnosed with breast cancer between 2000 and 2002, who had ≥ 36 months of Medicare eligibility prior to cancer, the event of interest; and 101,649 without cancer meeting the same Medicare eligibility criterion. Cancer patients were followed from 36 months before cancer diagnosis (prevalence period) up to 3 months after diagnosis (incidence period). Non-cancer patients were followed for up to 39 months after the beginning of Medicare eligibility. A sham date was inserted after 36 months to separate the prevalence and incidence periods. Using 36 months as the gold standard, the prevalence period was then shortened in 6-month increments to examine the impact on the number of conditions first detected during the incidence period. RESULTS: In the breast cancer cohort, shortening the prevalence period from 36 to 6 months increased the incidence rates (per 1,000 patients) of all conditions; for example: hypertension 196 to 243; diabetes 34 to 76; chronic obstructive pulmonary disease 29 to 46; osteoarthritis 27 to 36; congestive heart failure 20 to 36; osteoporosis 22 to 29; and cerebrovascular disease 13 to 21. Shortening the prevalence period has less impact on those without cancer. CONCLUSIONS: Selecting a short prevalence period to rule out pre-existing conditions can, through misclassification, substantially inflate estimates of incident conditions. In incidence studies based on Medicare claims, selecting a prevalence period of ≥24 months balances the need to exclude pre-existing conditions with retaining the largest possible cohort.

Completeness of prescription information in US commercial claims databases.

PURPOSE: Pharmacy commercial claims databases are widely used for pharmacoepidemiologic research. However, concerns have been raised that these databases may not fully capture claims for generic medications as a result of patients filling outside the context of their insurance. This has implications for many research activities and quality improvement programs. We sought to estimate the percentage of missing prescriptions in US commercial claims data using a novel design. METHODS: Using a large US commercial insurance database, we examined the completeness of warfarin prescription claims among patients with atrial fibrillation receiving regular medical follow-up and testing to manage warfarin dosing. We examined 14 different 6-month cross sections. Each cross section was treated independently to identify patients with at least two outpatient diagnoses of atrial fibrillation, two international normalized ratio tests, and one pharmacy claim. Trends in the percentage of patients with prescription claims for generic and branded warfarin were compared by year and 6-month periods using chi-square tests and generalized linear models adjusting for patient characteristics. RESULTS: Out of 111 170 patients, the percentage of patients with any warfarin drug decreased slightly from 91.7% (95% CI: 91.0, 92.4) in early 2003 to 87.1% (95% CI: 86.7-87.6) in late 2009 (χ(2) = 93.8, p < 0.0001). Over the same interval, the proportion of patients with generic warfarin exposure appearing increased significantly, whereas the proportion of patients with branded warfarin exposure decreased significantly. CONCLUSIONS: Our study supports the possibility that some prescriptions may not be captured in US commercial insurance databases.

Psychometric properties of the Osteoporosis-specific Morisky Medication Adherence Scale in postmenopausal women with osteoporosis newly treated with bisphosphonates.

BACKGROUND: Poor adherence to oral osteoporosis medications is common. Strategies for improving adherence begin with identification of the problem. The 8-item Morisky Medication Adherence Scale for self-reported adherence to antihypertensive medications was modified for assessing adherence to oral osteoporosis medications. An evaluation of the measurement properties of the Osteoporosis-Specific Morisky Medication Adherence Scale (OS-MMAS) was needed. OBJECTIVE: To examine the psychometric properties of the OS-MMAS in women with postmenopausal osteoporosis. METHODS: Five hundred women aged 55 years and older with osteoporosis who were newly prescribed daily or weekly oral bisphosphonates between May 15, 2010, and August 15, 2010, were randomly selected from Kaiser Permanente Southern California, a large integrated health care delivery system, and mailed a self-administered survey that included the 8-item OS-MMAS, Self-Efficacy for Appropriate Medication Use Scale (SEAMS), Beliefs about Medicines Questionnaire (BMQ), Treatment Satisfaction Questionnaire for Medication (TSQM), Gastrointestinal Symptom Rating Scale (GSRS), and 12-item Short-Form Health Survey (SF-12v2). OS-MMAS scores can range from 0 to 8, with higher scores indicating better medication adherence. Internal consistency reliability was evaluated using Cronbach α coefficient. Test-retest reliability was assessed using intraclass correlation coefficients (ICCs) in a subset of 102 participants. Construct validity was assessed using confirmatory factor analysis and correlations between OS-MMAS and related measures. RESULTS: Of 197 participants, 150 reported that they were still taking their bisphosphonate at the time of the survey and completed the OS-MMAS. Overall, 30.7%, 32.7%, and 36.7% had low, medium, and high OS-MMAS scores (<6, 6 to <8, and 8, respectively). Cronbach α was 0.82 and the ICC was 0.77. Convergent validity was supported by significant correlations with SEAMS, BMQ necessity, and TSQM scores. In confirmatory factor analysis, a single-factor scale was supported. CONCLUSIONS: The OS-MMAS showed strong psychometric properties with good reliability and construct validity and may provide a valuable assessment of self-reported medication adherence in women newly prescribed oral osteoporosis medications.

Surgical staging of early stage epithelial ovarian cancer: results from the CDC-NPCR ovarian patterns of care study.

OBJECTIVES: The objectives of this study were to determine the adequacy of surgical staging performed on surgically treated epithelial ovarian cancer (EOC) patients with apparent early stage disease and to determine if receipt of surgical staging had an influence on survival. METHODS: Detailed surgical staging information was collected from medical records for 721 patients diagnosed between 1998 and 2000 with EOC. Patients resided in California or New York and were identified through population-based cancer registries. RESULTS: Nearly 90% of patients had removal of the omentum and evaluation of bowel serosa and mesentery but only 72% had assessment of retroperitoneal lymph nodes and the majority of patients did not receive biopsies of other peritoneal locations. Only lymph node assessment (as well as node assessment combined with washings and omentectomy) had a statistically significant association with improved survival. The 5-year survival for women with node sampling was 84.2% versus 69.6% for those without this surgical procedure, and patients who did not have lymph node assessment had nearly twice the risk of death as those who did. When patients were stratified by receipt of chemotherapy, lack of node sampling had an effect only on patients who also had no chemotherapy (adjusted HR=2.2, CI=1.0-4.5). CONCLUSIONS: The results of this population-based study confirm the prognostic importance of surgical staging for women with EOC, and the important role of gynecologic oncologists in treating these patients. Adjuvant chemotherapy does not appear to further improve survival for those women who receive adequate surgical staging.

Trends in dual-energy X-ray absorptiometry in the United States, 2000-2009.

After a decade of policies encouraging dual-energy X-ray absorptiometry (DXA) use, Medicare incrementally decreased reimbursement for non-facility-based DXAs, effective 2007. This study quantifies trends in central DXA use before and after the reimbursement change. Using 2000-2009 claims data, we selected subjects aged 50+yr with Medicare supplemental or commercial insurance. The central site DXA test (using CPT codes) rate was calculated within each calendar quarter as the number of patients with a DXA test divided by the total number of patients. Piecewise linear regression was used to quantify change in DXA rates coincident with the 2007 reimbursement reductions. During 2000-2009, slightly over 5 million DXA tests were conducted. Annual rates for females with Medicare steadily increased until 2007, when they leveled off; a similar pattern was observed for the commercially insured. Regression modeling showed that pre-2007 rates increased annually by 0.76% (0.72-0.80) and 0.76% (0.70-0.82) among those with Medicare supplemental and commercial insurance, respectively, and over 2007-2009, rates changed annually by +0.07% (-0.05% to 0.19%) and -0.12% (-0.29% to 0.04%), respectively. During 2007-2009, there were 3.1 (2.4-3.8) and 4.0 (3.1-4.9) fewer tests per 100 person years for females with Medicare supplemental and commercial insurance, respectively, than would have been expected based on the pre-2007 trend. The post-2007 DXA rate was lower than what would have been expected had the observed trend of increasing annual DXA rates from 2000 to 2007 continued unabated beyond the Medicare reimbursement change in 2007. Continuing to provide access to DXA testing for women at increased risk of osteoporosis is important to providing high-quality care for metabolic bone disease in the United States.

Longitudinal, population-based study of racial/ethnic differences in colorectal cancer survival: impact of neighborhood socioeconomic status, treatment and comorbidity.

BACKGROUND: Colorectal cancer, if detected early, has greater than 90% 5-year survival. However, survival has been shown to vary across racial/ethnic groups in the United States, despite the availability of early detection methods. METHODS: This study evaluated the joint effects of sociodemographic factors, tumor characteristics, census-based socioeconomic status (SES), treatment, and comorbidities on survival after colorectal cancer among and within racial/ethnic groups, using the SEER-Medicare database for patients diagnosed in 1992-1996, and followed through 1999. RESULTS: Unadjusted colorectal cancer-specific mortality rates were higher among Blacks and Hispanic males than whites (relative rates (95% confidence intervals) = 1.34 (1.26-1.42) and 1.16 (1.04-1.29), respectively), and lower among Japanese (0.78 (0.70-0.88)). These patterns were evident for all-cause mortality, although the magnitude of the disparity was larger for colorectal cancer mortality. Adjustment for stage accounted for the higher rate among Hispanic males and most of the lower rate among Japanese. Among Blacks, stage and SES accounted for about half of the higher rate relative to Whites, and within stage III colon and stages II/III rectal cancer, SES completely accounted for the small differentials in survival between Blacks and Whites. Comorbidity did not appear to explain the Black-White differentials in colorectal-specific nor all-cause mortality, beyond stage, and treatment (surgery, radiation, chemotherapy) explained a very small proportion of the Black-White difference. The fully-adjusted relative mortality rates comparing Blacks to Whites was 1.14 (1.09-1.20) for all-cause mortality and 1.21 (1.14-1.29) for colorectal cancer specific mortality. The sociodemographic, tumor, and treatment characteristics also had different impacts on mortality within racial/ethnic groups. CONCLUSION: In this comprehensive analysis, race/ethnic-specific models revealed differential effects of covariates on survival after colorectal cancer within each group, suggesting that different strategies may be necessary to improve survival in each group. Among Blacks, half of the differential in survival after colorectal cancer was primarily attributable to stage and SES, but differences in survival between Blacks and Whites remain unexplained with the data available in this comprehensive, population-based, analysis.

Medicaid status and stage at diagnosis of cervical cancer.

OBJECTIVES: We examined whether Medicaid beneficiaries are more likely to be diagnosed with late-stage cervical cancer than women not enrolled in Medicaid. METHODS: Using the California Cancer Registry-Medicaid linked file, we identified 4682 women diagnosed during 1996-1999 with invasive cervical cancer. Multivariate logistic regression was used to evaluate the association between late-stage diagnosis and prediagnosis Medicaid status. RESULTS: Late-stage disease was diagnosed in 51% of Medicaid and 42% of non-Medicaid women. Relative to women without Medicaid coverage, adjusted odds ratios for late-stage diagnosis were 2.8 times higher among women enrolled in Medicaid at the time of their diagnosis and 1.3 times higher among those intermittently enrolled before being diagnosed. Vietnamese women were less likely than White women to have advanced disease; the adjusted odds for women in other racial/ethnic groups did not differ from those among Whites. Women of low socioeconomic status and older women were at increased risk. CONCLUSIONS: Women intermittently enrolled in Medicaid or not enrolled until their diagnosis were at greatest risk of a late-stage diagnosis, suggesting that more outreach to at-risk women is needed to ensure access to screening services.

Patterns of chemotherapy use for women with ovarian cancer: a population-based study.

PURPOSE: To evaluate adherence to published recommendations for chemotherapy for ovarian cancer patients in the general community and to identify factors associated with its use. PATIENTS AND METHODS: The study population consisted of 2,150 women residing in Northern California with a first diagnosis of primary epithelial ovarian cancer between January 1994 and December 1996. Patients were identified through the California Cancer Registry and their physicians were surveyed to supplement registry treatment information. RESULTS: Almost 89% of women younger than 75 years with International Federation of Gynecology and Obstetrics stage III or IV tumors received chemotherapy, with levels of treatment highest for women diagnosed at stage III. Patients 75 years of age and older were significantly less likely than younger women to receive chemotherapy (58.2% v 86.1%; P =.001) regardless of stage at diagnosis. Approximately 20% of patients younger than 55 years with early-stage (stage IC and II) cancer received no chemotherapy. Treatment in an American College of Surgeons hospital and treatment by a gynecologic oncologist increased the likelihood of receiving chemotherapy. Hospitalization for comorbid illness, race/ethnicity, census-based measures of socioeconomic status, and size or teaching status of hospital were all unrelated to probability of treatment after adjustment for other factors. Reasons reported most frequently by physicians for no treatment were lack of clinical indication and patient refusal. CONCLUSION: The results of this study suggest that, despite scientific evidence and published guidelines that advocate chemotherapy for most women with ovarian cancer, some groups of women did not receive optimum treatment.

Breast implants following mastectomy in women with early-stage breast cancer: prevalence and impact on survival.

BACKGROUND: Few studies have examined the effect of breast implants after mastectomy on long-term survival in breast cancer patients, despite growing public health concern over potential long-term adverse health effects. METHODS: We analyzed data from the Surveillance, Epidemiology and End Results Breast Implant Surveillance Study conducted in San Francisco-Oakland, in Seattle-Puget Sound, and in Iowa. This population-based, retrospective cohort included women younger than 65 years when diagnosed with early or unstaged first primary breast cancer between 1983 and 1989, treated with mastectomy. The women were followed for a median of 12.4 years (n = 4968). Breast implant usage was validated by medical record review. Cox proportional hazards models were used to estimate hazard rate ratios for survival time until death due to breast cancer or other causes for women with and without breast implants, adjusted for relevant patient and tumor characteristics. RESULTS: Twenty percent of cases received postmastectomy breast implants, with silicone gel-filled implants comprising the most common type. Patients with implants were younger and more likely to have in situ disease than patients not receiving implants. Risks of breast cancer mortality (hazard ratio, 0.54; 95% confidence interval, 0.43-0.67) and nonbreast cancer mortality (hazard ratio, 0.59; 95% confidence interval, 0.41-0.85) were lower in patients with implants than in those patients without implants, following adjustment for age and year of diagnosis, race/ethnicity, stage, tumor grade, histology, and radiation therapy. Implant type did not appear to influence long-term survival. CONCLUSIONS: In a large, population-representative sample, breast implants following mastectomy do not appear to confer any survival disadvantage following early-stage breast cancer in women younger than 65 years old.

Undiagnosed diabetes in breast, colorectal, lung, and prostate cancer: incidence and risk factors.

Our study describes the incidence and risk factors for undiagnosed diabetes in elderly cancer patients. Using Surveillance, Epidemiology, and End Results-Medicare data, we followed patients with breast, colorectal, lung, or prostate cancer from 24 months before to 3 months after cancer diagnosis. Medicare claims were used to exclude patients with diabetes 24 to 4 months before cancer (look-back period), identify those with diabetes undiagnosed until cancer, and construct indicators of preventive services, physician contact, and comorbidity during the look-back period. Logistic regression analyses were performed to identify factors associated with undiagnosed diabetes. Overall, 2,678 patients had diabetes undiagnosed until cancer. Rates were the highest in patients with both advanced-stage cancer and low prior primary care/medical specialist contact (breast 8.2%, colorectal 5.9%, lung 4.4%). Nonwhite race/ethnicity, living in a census tract with a higher percent of the population in poverty and a lower percent college educated, lower prior preventive services use, and lack of primary care and/or medical specialist care prior to cancer all were associated with higher (P ≤ 0.05) adjusted odds of undiagnosed diabetes. Undiagnosed diabetes is relatively common in selected subgroups of cancer patients, including those already at high risk of poor outcomes due to advanced cancer stage.

Declining rates of osteoporosis management following fragility fractures in the U.S., 2000 through 2009.

BACKGROUND: Clinical practice recommendations state that patients with fragility fractures should be evaluated for osteoporosis and treated for the disease if it is present. The purpose of this study was to assess osteoporosis evaluation and treatment patterns for patients with fragility fractures and assess whether anti-osteoporosis pharmacotherapy initiated immediately following a fragility fracture is associated with improved adherence to the treatment protocol. METHODS: This retrospective cohort study involved data from a large commercially insured population seen in the period from 2001 through 2009. Patients were community-dwelling individuals aged fifty years or older who had a new low-energy fracture at the hip, vertebra, wrist, or humerus with no evidence of a fragility fracture, osteoporosis treatment, malignant disease, or Paget disease for twelve months preceding the fracture. Rates of diagnostic testing and pharmacotherapy for osteoporosis within twelve months post-fracture were evaluated. Patients treated with oral bisphosphonates were evaluated to determine whether twelve-month adherence to the treatment protocol differed between those who had initiated therapy sooner (at zero to ninety days) and those who initiated it later (at ninety-one to 365 days) following the fracture. RESULTS: The 88,571 women and 41,984 men had an average age of 72.3 years and 70.5 years, respectively. Nineteen percent (16,464) of the women and 10% (4014) of the men initiated osteoporosis pharmacotherapy, and 30% (26,481) of the women and 15% (6427) of the men underwent diagnostic testing and/or pharmacotherapy following fracture. Treatment rates were highest following vertebral fracture and lowest following wrist or humeral fracture. Treatment rates significantly decreased over time (from 2001 through 2009). The average twelve-month adherence (medication possession ratio) was 56% and 61% among women and men, respectively. Adherence was similar between patients who had initiated treatment sooner after the fracture and those who had initiated it later after the fracture. CONCLUSIONS: Clinical guidelines for evaluation and treatment following fragility fracture were met for less than one-third of women and less than one-sixth of men. While primary fracture prevention remains the ideal, secondary prevention is critical and there is a need to reverse the downward trend in adherence to post-fracture guidelines.

The implications of age and comorbidity on survival following epithelial ovarian cancer: summary and results from a Centers for Disease Control and Prevention study.

BACKGROUND: Advances in treatment have improved ovarian cancer survival for most women, although less for the elderly. We report on this disparity and add further evidence about the relationship among age, comorbidity, and survival after ovarian cancer. METHODS: To examine age and comorbidity, Centers for Disease Control and Prevention (CDC)-funded cancer registries examined 2367 women residing in New York and Northern California diagnosed with epithelial ovarian cancer (1998-2000). Subjects were identified through tumor registries, treatment data were supplemented with physician survey, and comorbidity was identified through hospital discharge database linkages. Proportional hazards modeling was used to estimate the risk of death by age and comorbidity, adjusting for clinical and sociodemographic factors. RESULTS: Crude survival at 1 year and 3 years was 71.9% and 50.1%, respectively. Within stage, age-specific survival rates were lower in the oldest groups, particularly for those with advanced disease. For age 75+, 3-year survival was 13% vs. 50% in those <35 (stage IV). For all stages, women without comorbidity had higher survival rates than those with comorbidity. Older age and comorbidity were both associated with advanced stage and less aggressive treatment. The adjusted risk of death was 40%, and it was 80% higher for the 65-74 and 75+ groups, respectively, compared to women 35-64 (p<0.00). Comorbidity increased the risk of death by 40% (p<0.00). CONCLUSIONS: This study confirmed the independent adverse effects of age and comorbidity on survival following ovarian cancer. As the population ages, the co-occurrence of ovarian cancer and comorbidity will increase. Further work identifying critical conditions that impact survival could potentially inform complex treatment decisions.

Survival by histologic subtype in stage IV nonsmall cell lung cancer based on data from the Surveillance, Epidemiology and End Results Program.

BACKGROUND: The role of histology in the targeted management of nonsmall cell lung cancer (NSCLC) has garnered renewed attention in recent years. We provide contemporary population-based estimates of survival and an assessment of important prognostic factors in stage IV NSCLC by major histologic subtype. METHODS: Using data from the Surveillance, Epidemiology and End Results (SEER) Program, we stratified 51,749 incident stage IV NSCLC patients (1988-2003 with follow-up through 2006) by major histologic subtype. We used Kaplan-Meier and Cox proportional hazards methods to describe overall survival and the prognostic influence of select patient, tumor, and treatment characteristics for each histologic subgroup. RESULTS: Survival was highest in patients with bronchioloalveolar adenocarcinoma (1-year survival: 29.1%) and lowest in those with large cell tumors (1-year survival: 12.8%). Diagnosis in later years, female gender, younger age, either Asian/Pacific Islander or Hispanic race/ethnicity, lower tumor grade, and surgery or beam radiation as part of first-line treatment were generally independently associated with a decreased risk of death, but the prognostic significance of some of these factors (age, ethnicity, tumor grade) varied according to histologic subtype. CONCLUSION: Findings demonstrate a poor prognosis across histologic subtypes in stage IV NSCLC patients but highlight differences in both absolute survival and the relative importance of select prognostic factors by histologic subclassification. More research using other sources of population-based data could help clarify the role of histology in the presentation, management, and prognosis of late-stage NSCLC.

Validity of cancer registry medicaid status against enrollment files: implications for population-based studies of cancer outcomes.

BACKGROUND: Poor access to or inadequate health insurance contributes to disparities in cancer incidence and mortality. Cancer registry "payer source" data is collected by many cancer registries in the United States and has been used to compare cancer outcomes across insurance types. OBJECTIVES: We evaluated the validity of cancer registry data on patient Medicaid status against enrollment data from Medi-Cal, California's Medicaid program. METHODS: Data from the statewide California Cancer Registry for persons under age 65 years diagnosed with 1) any cancer in 1998 and 1999 or 2) with invasive cervical cancer between 1996 and 1999 were obtained and linked probabilistically to Medi-Cal enrollment files. We compared registry Medicaid status, determined from payer source information, against linkage results and used crosstabulations to calculate sensitivity, specificity, and positive predictive value. These measures were compared across different hospital and patient characteristics and cancer types. RESULTS: Cancer registry Medicaid status data had poor sensitivity (48%), good specificity (98%), and moderate positive predictive value (77%). Measures of validity did not vary substantially by cancer type, stage, patient age, sex, vital status, race/ethnicity, socioeconomic status, or diagnosing hospital size. Registry data undercounted the number of Medicaid patients by 52% and incorrectly assigned Medicaid as a payer to approximately 2% of patients. CONCLUSIONS: As a result of the poor validity of cancer registry Medicaid status data, caution should be used when interpreting cancer outcomes by insurance type calculated from registry payer source data. Linkage of registry data to Medicaid enrollment files represents a more accurate means of identifying Medicaid insurance status.

Cancer surveillance research: a vital subdiscipline of cancer epidemiology.

Public health surveillance systems relevant to cancer, centered around population-based cancer registration, have produced extensive, high-quality data for evaluating the cancer burden. However, these resources are underutilized by the epidemiology community due, we postulate, to under-appreciation of their scope and of the methods and software for using them. To remedy these misperceptions, this paper defines cancer surveillance research, reviews selected prior contributions, describes current resources, and presents challenges to and recommendations for advancing the field. Cancer surveillance research, in which systematically collected patient and population data are analyzed to examine and test hypotheses about cancer predictors, incidence, and outcomes in geographically defined populations over time, has produced not only cancer statistics and etiologic hypotheses but also information for public health education and for cancer prevention and control. Data on cancer patients are now available for all US states and, within SEER, since 1973, and have been enhanced by linkage to other population-based resources. Appropriate statistical methods and sophisticated interactive analytic software are readily available. Yet, publication of papers, funding opportunities, and professional training for cancer surveillance research remain inadequate. Improvement is necessary in these realms to permit cancer surveillance research to realize its potential in resolving the growing cancer burden.

Survival of Californian women with epithelial ovarian cancer, 1994-1996: a population-based study.

OBJECTIVE: The objective was to identify demographic, clinical, and provider characteristics that might influence cancer survival in a cohort of Northern California women using a population-based cancer registry. METHODS: We used California Cancer Registry data to evaluate survival in 1051 Northern California women who were diagnosed with epithelial ovarian cancer between 1994 and 1996 and underwent a surgical procedure for their cancer. Chemotherapy data from the cancer registry were supplemented with a physician survey and medical record review. Database linkages with census and hospital discharge data provided socioeconomic and comorbidity measures. Kaplan-Meier method was used to generate survival curves and multivariate Cox proportional hazard models were used to evaluate the effect of different factors on survival. RESULTS: Crude 5-year survival was 82, 57, 28, and 10% for women with FIGO stage IC, II, III, and IV disease, respectively. Adverse survival was most strongly influenced by advanced stages III and IV with a hazards ratio ranging from 8 to 11.8 compared to stage IC disease. Multivariate analysis also identified other adverse factors including high grade and other adverse histologies, age over 45, and rural location. Chemotherapy decreased the risk of death by 50% if the patient had advanced-stage disease. Medical comorbidity increased the risk of death by 40%. Survival was not influenced by race/ethnicity, socioeconomic status, physician specialty, or hospital characteristics. CONCLUSION: Advanced age remains an adverse prognostic factor even after adjustment for treatment and comorbidity factors. These results also suggest that there may be important regional differences in ovarian cancer survival.