Biomedical subjects

William W Davis

Publications and source records attributed to William W Davis.

16 recordsLinked to original sources

PubMed2007

Patient time costs associated with cancer care.

BACKGROUND: Although costs of medical care for cancer have been investigated extensively, patient time costs associated with cancer care have rarely been estimated systematically. In this study, we estimated patient time costs associated with cancer care in patients aged 65 years and older in the United States. METHODS: We identified 763,527 patients with breast, colorectal, corpus uteri, gastric, head and neck, lung, melanoma of the skin, ovary, prostate, renal, and urinary bladder cancers from linked Surveillance, Epidemiology, and End Results-Medicare files and 1,145,159 noncancer control subjects among Medicare enrollees who were matched by sex, age-group, and geographic location. Frequency of service use was calculated by category for patients and control subjects using Medicare claims data from 1995 to 2001. For each service category, time estimates were combined with service frequency and an hourly value of patient time. Net patient time costs were summed in the initial, continuing, and last-year-of-life phases of care for each tumor site. Net time cost estimates for the initial phase of care were applied to national estimates of numbers of new cancers in 2005 to obtain national time costs for the initial phase of care. RESULTS: Net patient time costs during the initial phase of care ranged from 271 dollars (95% confidence interval [CI] = 213 dollars to 329 dollars) and 842 dollars (95% CI = 806 dollars to 878 dollars) for melanoma of the skin and prostate cancer, respectively, to 5348 dollars (95% CI = 4978 dollars to 5718 dollars) and 5605 dollars (95% CI = 5273 dollars to 5937 dollars) for gastric and ovarian cancers, respectively. Net patient time costs for care during the last year of life ranged from 1509 dollars (95% CI = 1343 dollars to 1675 dollars) for melanoma of the skin to 7799 dollars (95% CI = 7433 dollars to 8165 dollars), 7435 dollars (95% CI = 7207 dollars to 7663 dollars), and 7388 dollars (95% CI = 7018 dollars to 7758 dollars) for gastric, lung, and ovarian cancers, respectively. In 2005, patient time costs for the initial phase of care were 2.3 billion dollars. CONCLUSIONS: Patient time costs for cancer care in the United States are substantial and vary by tumor site and phase of care, likely reflecting differences in stage at diagnosis and availability and intensity of treatment.

Aged↗

PubMed2006

Racial differences in colorectal cancer test use by Medicare consumers.

BACKGROUND: Lower use of colorectal cancer (CRC) screening has been suggested as a factor in higher rates of CRC incidence and mortality among African Americans. Racial differences in colorectal cancer test use are not well understood. METHODS: The study sample included respondents aged 50 to 80 to a 2001 telephone survey of Medicare consumers from two states. The analyses, initiated in 2004, were limited to respondents with no history of CRC (n = 1901). Three CRC tests were examined: fecal occult blood tests (FOBTs), sigmoidoscopy, and colonoscopy. Type of testing and testing according to Medicare coverage intervals by race were compared. Odds ratios (ORs) and 95% confidence intervals (CIs) were obtained from unadjusted and adjusted models to assess the independent associations between race and test use. RESULTS: Adherence to the Medicare-covered intervals for CRC tests was low (56.8% for whites, 39.1% for African Americans), and did not significantly differ by race after adjustment. African Americans were, however, significantly less likely to have ever been tested (OR = 0.48, 95% CI = 0.33-0.70) and more likely to have had an endoscopic test than an FOBT (OR = 3.06, 95% CI = 1.70-5.51). CONCLUSIONS: The type of test used to screen for colorectal cancer has important implications for compliance with recommended screening intervals. Understanding reasons for racial differences in CRC test use may help identify approaches to increasing test use in the Medicare population.

Aged↗

PubMed2006

Barriers to colorectal cancer screening among Medicare consumers.

BACKGROUND: Few studies have examined lack of physician recommendation and other reasons for under-utilization of colorectal cancer (CRC) screening in the Medicare population. METHODS: Data from a telephone survey conducted in 2001 in a random sample of Medicare consumers residing in North and South Carolina were used to examine barriers to CRC screening, focusing on consumers' reports of receiving a physician's recommendation to obtain CRC screening and reasons for not being screened. Analyses were restricted to respondents with no history of CRC (n = 1901). Descriptive statistics were used to characterize respondents' CRC screening status, receipt of a physician's recommendation for screening, and reasons for not being screened. Logistic regression modeling was used to examine factors associated with receiving a physician recommendation for fecal occult blood test, sigmoidoscopy, colonoscopy, any endoscopy, and any CRC test. RESULTS: Thirty-one percent of Medicare consumers had never been tested for CRC, and 18% had been tested but were not current with Medicare-covered intervals. Overall, 28% reported not receiving a physician recommendation for screening. Predictors of receiving a physician recommendation included sociodemographic (younger age, white race, more education), health status (increased CRC risk, comorbidity), and healthcare access (had a routine/preventive care visit in the past 12 months) factors. Lack of knowledge/awareness and the physician not ordering the test were commonly cited reasons for not having CRC tests. CONCLUSIONS: Colorectal cancer screening was under-utilized by Medicare consumers in two states, and lack of physician recommendation was an important contributing factor. Providing a benefit under the Medicare program does not ensure its widespread use by consumers or their physicians.

Aged↗

PubMed2006

Exercise preconditioning reduces brain damage and inhibits TNF-alpha receptor expression after hypoxia/reoxygenation: an in vivo and in vitro study.

Exercise reduces ischemia and reperfusion injury in rat stroke models. We investigated whether gradual increases in tumor necrosis factor-alpha (TNF-alpha) reported during exercise down-regulates expression of TNF-alpha receptors I and II (TNFRI and II) in stroke, leading to reduced brain damage. Adult male Sprague Dawley rats were subjected to 30 minutes of exercise on a treadmill each day for 3 weeks. Then, stroke was induced by a 2-hour middle cerebral artery (MCA) occlusion using an intra-luminal filament. Expressions of TNFRI and II mRNA in the brain were detected using a real-time reverse transcriptase-polymerase chain reaction (RT-PCR). Protein expressions of TNFRI and II were determined by enzyme-linked immunoabsorbant assay (ELISA) in serum and brain homogenates. Spatial distribution of TNF-alpha receptors in brain regions was determined with immunocytochemistry. In human umbilical vein endothelial cells (HUVEC), we addressed the causal effect of TNF-alpha pretreatment on TNF I and II expression using ELISA and real-time PCR. In exercised rats after stroke, brain infarct was significantly (p<0.01) reduced in the entire MCA supplied regions, associated with a mild expression of TNFRI and II mRNA and protein. The TNF-alpha receptors were restricted to the ischemic core. In contrast, a robust expression of TNFRI and II molecules was found in non-exercised rats subjected to similar ischemia/reperfusion insults. An in vitro study revealed a causal link between TNF-alpha pretreatment and reduced cellular expression of TNF-alpha receptors under hypoxic/reoxygenated conditions. Our results suggest that reduced-brain damage in ischemic rats after exercise preconditioning may be attributable to the reduced expression of TNF-alpha receptors. Chronically increased TNF-alpha expression was also found to reduce TNFI and II responding to acute ischemia/reperfusion insult.

Animals↗

PubMed2005

Cancer screening and risk factor rates among American Indians.

OBJECTIVES: We examined cancer screening and risk factor patterns in California using 4 different statistical tabulations of American Indian and Alaska Native (AIAN) populations. METHODS: We used the 2001 California Health Interview Survey to compare cancer screening and risk factor data across 4 different tabulation approaches. We calculated weighted prevalence estimates by gender and race/ethnicity for cancer screening and risk factors, sociodemographic characteristics, and access to care variables. We compared AIAN men and women with members of other racial groups and examined outcomes among AIAN men and women using the 4 tabulation methods. RESULTS: Although some differences were small, in general, screening and risk factor rates among American Indians/Alaska Natives were most similar to rates among Whites when the most inclusive multiracial tabulation approach was used and least similar when the more exclusive US census "single-race" approach was used. CONCLUSIONS: Racial misclassification and undercounting are among the most difficult obstacles to obtaining accurate and informative data on the AIAN population. Our analysis suggests some guidelines for overcoming these obstacles.

California↗

PubMed2005

Do patients consistently report comorbid conditions over time?: results from the prostate cancer outcomes study.

BACKGROUND: Comorbidity is an important dimension of patient health status. However, limited attention has been given to assessing the reliability of patient-reported data on comorbid conditions. OBJECTIVES: We sought to evaluate the consistency of self-report of 12 comorbid conditions at 3 distinct time points and examine the sociodemographic, clinical, health status, and survey factors associated with reliability. STUDY DESIGN: We undertook a longitudinal cohort analysis of survey and medical record abstract data obtained from a population-based sample of 3095 prostate cancer survivors. METHODS: Consistent and inconsistent response patterns were assessed using descriptive statistics and regression modeling. RESULTS: More than half of the cohort demonstrated consistent responses to all comorbid condition questionnaire items. Arthritis had the highest (13%) and liver disease the lowest (1%) proportion of inconsistent responses. Older age, lower income, and poorer general and mental health status were significant predictors of inconsistent responses. Subset analyses of the 4 most prevalent comorbid conditions (ie, arthritis, diabetes, hypertension, and depression) showed that respondents who reported that they were limited by, or taking prescription medicine for, the condition were more likely to provide consistent responses than those neither limited nor taking medicine. Response consistencies of 92% or better were obtained for 11 of the 12 conditions. CONCLUSIONS: Men with a relatively recent prostate cancer diagnosis are generally able to provide reliable reports of their concomitant health conditions. To increase the likelihood of obtaining reliable data, investigators should consider ascertaining condition severity and current medical management when querying subjects about comorbid conditions in surveys.

Adult↗

PubMed2005

Estimating patient time costs associated with colorectal cancer care.

BACKGROUND: Nonmedical costs of care, such as patient time associated with travel to, waiting for, and seeking medical care, are rarely measured systematically with population-based data. OBJECTIVES: The purpose of this study was to estimate patient time costs associated with colorectal cancer care. METHODS: We identified categories of key medical services for colorectal cancer care and then estimated patient time associated with each service category using data from national surveys. To estimate average service frequencies for each service category, we used a nested case control design and SEER-Medicare data. Estimates were calculated by phase of care for cases and controls, using data from 1995 to 1998. Average service frequencies were then combined with estimates of patient time for each category of service, and the value of patient time assigned. Net patient time costs were calculated for each service category, summarized by phase of care, and compared with previously reported net direct costs of colorectal cancer care. RESULTS: Net patient time costs for the 3 phases of colorectal cancer care averaged dollar 4592 (95% confidence interval [CI] dollar 4427-4757) over the 12 months of the initial phase, dollar 2788 (95% CI dollar 2614-2963) over the 12 months of the terminal phase, and dollar 25 (95% CI: dollar 23-26) per month in the continuing phase of care. Hospitalizations accounted for more than two thirds of these estimates. Patient time costs were 19.3% of direct medical costs in the initial phase, 15.8% in the continuing phase, and 36.8% in the terminal phase of care. CONCLUSIONS: Patient time costs are an important component of the costs of colorectal cancer care. Application of this method to other tumor sites and inclusion of other components of the costs of medical care will be important in delineating the economic burden of cancer in the United States.

Colorectal Neoplasms↗

PubMed2005

Pregnancy hormone concentrations across ethnic groups: implications for later cancer risk.

A variety of in utero factors have been associated with risk of adult cancers, particularly birth weight, toxemia, and gestational age. These factors are thought to reflect hormonal exposures during pregnancy. We hypothesized that the prenatal hormonal milieu may explain part of the variation in cancer rates across ethnic groups, for example, the higher incidence of breast cancer in the Caucasian compared with Hispanic women and the higher incidence of prostate and lower incidence of testicular cancers among African-Americans compared with Caucasians. We measured hormones in early pregnancy blood samples from three ethnic groups in a health care plan in Boston, MA. Mean levels of androstenedione, testosterone, estrone, and prolactin were significantly lower in Caucasian women compared with Hispanic women. Although not statistically significant, estradiol levels were lower in Caucasian compared with Hispanic or African-American women. Concentrations of androstenedione, testosterone, and progesterone were notably higher in African-American compared with Caucasian or Hispanic women. These data are consistent with hypotheses that in utero hormonal exposures may explain some of the ethnic group differences in cancer risk.

Adult↗

PubMed2004

Latent variable modelling of recovery trajectories: sexual function following radical prostatectomy.

As treatments improve and survival time lengthens, the course of recovery and long-term quality of life (QoL) is of greater interest. The application of latent class growth models to longitudinal QoL data provides unique insights into recovery that are not evident with marginal analyses. We examine this approach in the context of a large population-based observational study. This is the first attempt to characterize individuals' recovery over time following prostate cancer surgery, and to determine factors associated with varying recovery experiences of prostate cancer patients. Four major patterns emerged that illustrate typical patterns of recovery following radical prostatectomy. Given a man's baseline data, this method produces estimates of the probability of belonging to each recovery class. The method is presented as a useful tool for identifying hypotheses associated with recovery and potential antecedents of importance.

Erectile Dysfunction↗

PubMed2004

Five-year outcomes after prostatectomy or radiotherapy for prostate cancer: the prostate cancer outcomes study.

BACKGROUND: Men treated for clinically localized prostate cancer with either radical prostatectomy or external beam radiotherapy usually survive many years with the side effects of these treatments. We present treatment-specific quality-of-life outcomes for prostate cancer patients 5 years after initial diagnosis. METHODS: The cohort consisted of men aged 55-74 years who were newly diagnosed with clinically localized prostate cancer in 1994-1995 and were treated with radical prostatectomy (n = 901) or external beam radiotherapy (n = 286). We used clinical and quality-of-life data previously collected at the time of diagnosis (i.e., baseline) and at the 2-year follow-up and data newly collected at 5 years after diagnosis to compare urinary, bowel, and sexual function and to examine temporal changes in those functions. Odds ratios (ORs) and adjusted percentages were calculated by logistic regression. All statistical tests were two-sided. RESULTS: At 5 years after diagnosis, overall sexual function declined in both groups to approximately the same level. However, at 5 years after diagnosis, erectile dysfunction was more prevalent in the radical prostatectomy group than in the external beam radiotherapy group (79.3% versus 63.5%; OR = 2.5, 95% confidence interval [CI] = 1.6 to 3.8). Approximately 14%-16% of radical prostatectomy and 4% of external beam radiotherapy patients were incontinent at 5 years (OR = 4.4, 95% CI = 2.2 to 8.6). Bowel urgency and painful hemorrhoids were more common in the external beam radiotherapy group than in the radical prostatectomy group. All of these differences remained statistically significant after adjustment for confounders and for differences between treatment groups in some baseline characteristics. CONCLUSIONS: At 5 years after diagnosis, men treated with radical prostatectomy for localized prostate cancer continue to experience worse urinary incontinence than men treated with external beam radiotherapy. However, the two treatment groups were more similar to each other with respect to overall sexual function, mostly because of a continuing decline in erectile function among the external beam radiotherapy patients between years 2 and 5.

Aged↗

PubMed2004

Burden of illness in cancer survivors: findings from a population-based national sample.

BACKGROUND: Population trends in aging and improved cancer survival are likely to result in increased cancer prevalence in the United States, but few estimates of the burden of illness among cancer survivors are currently available. The purpose of this study was to estimate the burden of illness in cancer survivors in a national, population-based sample. METHODS: A total of 1823 cancer survivors and 5469 age-, sex-, and educational attainment-matched control subjects were identified from the 2000 National Health Interview Survey. Multiple measures of burden, including utility, a summary measure of health, and days lost from work, were compared using two-sided tests of statistical significance for the two groups overall and for subgroups stratified by tumor site and time since diagnosis. RESULTS: Compared with matched control subjects, cancer survivors had poorer outcomes across all burden measures (P<.01). Cancer survivors had lower utility values (0.74 versus 0.80; P<.001) and higher levels of lost productivity and were more likely to report their health as fair or poor (31.0% versus 17.9%; P<.001) than matched control subjects. Cancer survivors reported statistically significantly higher burden than did control subjects across tumor sites and across time since diagnosis (i.e., within the past year, 2-5 years, 6-10 years, and > or =11 years for the majority of measures. CONCLUSIONS: Cancer survivors have poorer health outcomes than do similar individuals without cancer across multiple burden measures. These decrements are consistent across tumor sites and are found in patients many years following reported diagnosis. Improved measurement of long-term burden of illness will be important for future prospective research.

Activities of Daily Living↗

PubMed2003

Racial/ethnic patterns of care for cancers of the oral cavity, pharynx, larynx, sinuses, and salivary glands.

BACKGROUND: Among Americans, both incidence and mortality from cancers of the larynx, oral cavity, and pharynx are higher for African Americans than whites and for men than women. In addition, the 5-year survival rates for these sites are significantly lower for African Americans than whites for each disease stage, particularly among African American males. We examine racial/ethnic variation in tumor characteristics, treatment practices, and their relationship to survival for cancers of the oral cavity, pharynx, larynx, nasal cavity and salivary glands. METHODS: Eligible individuals were age 20 or older and newly diagnosed with a primary invasive cancer of the oral cavity (excluding the lip), pharynx, larynx, sinuses or salivary glands in 1997 reported to one of nine National Cancer Institute's Surveillance Epidemiology and End Results Registries (SEER). Persons meeting the eligibility criteria for each registry were first stratified by race/ethnic group and stage then selected by random sampling within strata. RESULTS: We found racial/ethnic differences in diagnoses at specific anatomic sites, disease stage and treatment. African Americans less frequently received a cancer directed treatment than both whites and Hispanics and when treated were generally less likely to receive cancer-directed surgery. In multivariate analysis, the receipt of any cancer directed treatment was significantly associated with race and age group. African Americans and Hispanics had poorer, but not significantly so, overall, but not cancer-specific, survival. CONCLUSION: We found racial differences in the receipt of cancer treatment among patients diagnosed with selected head and neck cancers. We also found a less favorable distribution of stage for African Americans and Hispanics when compared with whites. The differences in stage we noted and the lower rates of oral cancer screening previously reported for these populations suggests that differential rates of early detection may contribute to racial differences in survival and mortality from cancers of the oral cavity and pharynx. Therefore, we conclude that more equitable receipt of cancer treatment along with preventive measures and earlier detection will help reduce racial/ethnic disparities in survival and mortality from cancers of the oral cavity, pharynx and larynx.

Adult↗

PubMed2003

Another round in the mammography controversy.

PURPOSE: The October 2001 publication of a meta-analysis questioning the scientific basis for recommending screening mammography sparked yet a new flame of controversy about this issue. We conducted a national survey in March 2002 to provide information about women's perspectives on the issues, including the evidence regarding the efficacy of mammography and, ultimately, their intentions to continue screening. METHODS: We added 12 questions to a national telephone omnibus survey in March 2002 to assess women's reactions to the ongoing debate. Responses were collected over three waves of the twice-weekly survey to obtain data from 733 women between the ages of 40 and 69. The sample was weighted to the U.S. population for census region, age, race, ethnicity, and educational attainment. RESULTS: Consistent with prior studies, most women were getting regular mammograms (78%) (95% confidence interval [CI] 75%-81%), >90% believed that mammography is effective in detecting breast cancer (95%) (95% CI 93%-97%) and in reducing breast cancer mortality (93%) (95% CI 91%-96%), and only about 22% (95% CI 19%-25%) said they were confused. Logistic regression analyses revealed sociodemographic differences among women who had heard about the controversy and who reported some confusion about mammograms. Women with lower levels of education, younger women, and those residing in nonmetropolitan areas were significantly less likely to be aware of the controversy. Although a majority of women said they were not confused about mammography, minority women and women with lower education levels were more likely to report being confused. There were no significant demographic differences in intentions to get future mammograms. Women who were concerned about getting breast cancer were much more likely to be planning to have future mammograms than women who were not at all concerned (odds ratio [OR] 3.63; 95% CI 2.37, 5.56). Likewise, respondents who said that they had enough information to make decisions whether to get future mammograms were much more likely to plan on getting screened than women who said they did not have enough information (OR 2.47; 95% CI 1.14, 5.40). CONCLUSIONS: These results do not suggest that controversy leads to lower rates of adherence. They do indicate that some women lack the information needed to make informed decisions about mammography.

Adult↗

PubMed2003

Descriptive methods for evaluation of state-based intervention programs.

In this article, the authors discuss program evaluation of intervention studies when the outcome of interest is collected routinely at equally spaced intervals of time. They illustrate concepts using data from the American Stop Smoking Intervention Study, where the outcome is state per capita tobacco consumption. States differ widely in mean tobacco consumption, and these differences should be accounted for in the analysis. A large difference in the variance of the intervention effect may be obtained depending on whether the variation in the between-state effects are considered. The confidence limits obtained by ignoring between-state effects are too optimistic in many cases.

Humans↗

PubMed2003

The hormone therapy dilemma: women respond.

OBJECTIVE: In the wake of the premature end of the Women's Health Initiative (WHI) study, we sought to assess women's knowledge of and attitudes about hormone therapy (HT) study findings and to appraise women's responses and intentions. METHODS: Between July 26 and August 6, 2002 a national random-digit-dialing telephone survey was conducted in a sample of households that included women 40 to 79 years old. RESULTS: Sixty-four percent of the 819 women interviewed had heard something about HT study results from the media or from talking with others, and 74% were confused about HT use. Another 57% were worried about how the findings might affect them, and 79% were interested in obtaining additional information about HT Only 24% of those who had heard something had actually sought additional information. Logistic regression findings suggested that women currently taking HT were most likely to be aware and informed. They also were more likely to be confused, worried, or to need or to seek additional information. Older women were less likely to be confused or worried or to need or seek additional information. More highly educated women were more likely to be aware and less likely to be confused or uninformed, but were more likely to have sought additional information. CONCLUSION: The Women's Health Initiative study provided a clear message about health risks and benefits of HT use. An important next step is to continue to convey accurate information to women, health providers, and the media so that women can make informed decisions about HT.

Adult↗

PubMed2002

Colorectal cancer screening with double-contrast barium enema: a national survey of diagnostic radiologists.

OBJECTIVE: This article describes diagnostic radiologists' colorectal cancer screening activities and beliefs about screening effectiveness and future capacity for screening with double-contrast barium enema, and compares radiologists' opinions about colorectal cancer screening with those of primary care physicians. MATERIALS AND METHODS: We surveyed a nationally representative sample of diagnostic radiologists. Of 381 eligible radiologists, 312 (82%) responded. Descriptive statistics and chi-square tests were used to assess radiologists' opinions about double-contrast barium enema volume and capacity and to compare radiologists' beliefs about colorectal cancer screening with those of primary care physicians. Logistic regression was used to identify characteristics of radiologists who receive referrals for or perform a higher volume of screening double-contrast barium enema and of those who expect the volume of double-contrast barium enemas to increase. RESULTS: Seventy-five percent of radiologists said that double-contrast barium enema is a "very effective" colorectal cancer screening procedure compared with 33% of primary care physicians. Although 86% of radiologists reported performing one or more screening double-contrast barium enema procedures during a typical month, only 27% indicated that they did so 11 or more times. Fifteen percent of radiologists said that their double-contrast barium enema volume had increased over the past 3 years, and 50% expect an increase over the next 3 years. Only 8% said that the capacity of facilities and personnel to meet the demand for double-contrast barium enemas in their geographic area of practice is inadequate. Geographic region and belief in double-contrast barium enema efficacy were predictors of double-contrast barium enema volume and referrals. CONCLUSION: Most diagnostic radiologists perform colorectal cancer screening with double-contrast barium enema, but procedure volumes are modest. Because primary care physicians view double-contrast barium enema less positively than do radiologists, radiologists' expectations for an increased volume of double-contrast barium enemas over the next few years may not be realized.

Adult↗