STATISTICAL MODELS FOR ANALYSIS OF DOSE-RESPONSE DATA

In this paper we propose three families of functional models for analysis of dose-response data. The first family is for modeling data which have a steep sloping line for an ascending portion of the response curve and a plateau representing maximum response or a sloping line representing little response at higher application levels. The second family is for modeling data which represent a steep sloping line on the ascending portion of the response curve and a declining curvature for declining response at higher application levels. The third family is for fitting data which show an initial plateau followed by increased or decreased response, and finally a plateau representing maximum response. One of the advantages of using these families for modeling the dose-response data is that the join points of the response curves are not considered parameters to be estimated, nor their estimates considered random variables in the estimation process. The uses of the families are illustrated using them in fitting the fertilizer response data of single nutrient experiments. The problem of modeling the multinutrient response data is addressed and recently developed methods are briefly discussed

Racial and Ethnic Differences in Cardiovascular Disease Risk Factors in U.S. Older Women: Findings from Behavioral Risk Factor Surveillance Survey, 2003 & 2004

The purpose of this study was to examine racial and ethnic variations in the modifiable CVD risk factors in older women (65 years and older). The study data was drawn from the merged 2003 and 2004 national Behavioral Risk Factor Surveillance Survey (BRFSS). Multinomial regression analyses for indicator outcome and multiple logistic regression analyses for binary outcomes were performed to determine the relationship between each of the six dependent variable and the independent variables. Compared to older white women, older black women had significantly higher odds of hypertension, diabetes and obesity. No significant association was found between Hispanics and hypertension. However Hispanics were found to be more likely to have diabetes and no leisure-time physical activity compared to whites. Hispanics were also found to have lower odds of smoking compared to whites. American Indian and Alaskan Native (AIAN) s were found to have significantly higher odds of diabetes and obesity compared to whites. No significant association between AIANs and smoking was found. Overall, there are striking racial and ethnic differences in the CVD risk factors among older U.S women after controlling for socio-economic status. It is evident from these findings that in designing interventions to reduce cardiovascular risks for elderly women, clearly “one size does not fit all.” These findings highlight the need for development and implementation of appropriate public health programs aimed at these various target communities

Palestinian Health Institutions: Finding a Way Forward in the Wake of the Second Intifada

The strength of Hamas in Palestinian elections in early 2006 reshuffled the cards in the game of Middle East politics. Many astonished observers have sought an explanation for this political change. But the election result should not have been so surprising. Hamas has earned a reputation of clean governance and compassion for the poor, unlike the Fatah-led Palestinian Authority. Hamas has had a strong presence in the health sector which helped establish its legitimacy and popularity. This paper reviews bilateral and multilateral aid to Palestinians following the second intifada and argues that not enough was done by the international community to bolster health services of the Palestinian Authority. This left a void that Hamas and other charitable organizations have filled. The health sector remains strategic and its assimilation with the Palestinian Authority should be sought. Comprehensive policy toward the Middle East and other developing regions should integrate social welfare programs with global security interests

The balanced scorecard framework-A case study of patient and employee satisfaction: What happens when it does not work as planned?

Background: The successful utilization of the balanced scorecard (BSC) framework in health care has been demonstrated in the literature. Given these successes, a financially struggling hospital implemented a BSC framework intervention which attempted a culture change centered upon patient satisfaction which it hoped would translate to improved financial stability. Despite the evidence of BSC successes, the intervention, entitled Route 99, did not succeed in this hospital. Purpose: This case study was conducted to identify learnable lessons and confounding factors associated with the successes and failures of Route 99. Metrics for patient satisfaction and employee satisfaction were examined as reflections of the intervention, the BSC framework, and the confounding financial condition of the hospital. Methodology: Through case study methodology, mean quarterly patient satisfaction scores tabulated by an outside vendor for inpatient and outpatient services were divided into four time intervals and compared through analysis of variance. Employee satisfaction was measured through a hospital-provided 12-question employee survey, administered through convenience sampling at the beginning and 7 months into Route 99. Each question utilized a 5-point Likert scale and generated two samples which were verified for sample independence through chi-square analysis. Mann-Whitney U test was used for comparison. Findings: Inpatient patient satisfaction scores exhibited a nonsignificant upward trend. However, the analysis of variance demonstrated a significant rise in outpatient patient satisfaction (p \u3c .05). An interesting finding was that employee satisfaction declined (p \u3c .05) significantly for supervisors and directors in three areas. The inverse relationship between patient satisfaction and employee satisfaction is in contrast to that found in the literature by the authors. Practice Implications: Examination of the BSC framework, the hospital\u27s financial standing, and the metrics for patient satisfaction and employee satisfaction illuminated the importance of management transparency, leadership support, appropriate metric selection, and the strength of the BSC under turbulent circumstances

Disparities in Access to Healthcare: The Case of a Drug and Alcohol Abuse Detoxification Treatment Program among Minority Groups in a Texas Hospital

The authors analyzed ethnic/racial disparities in healthcare access and length of stay from a defined population of individuals seeking medical detoxification services at a hospital in Texas. Results indicated Blacks were more likely to be insured compared with Whites, mostly by public insurance, but this did not hold for Hispanics, who were about three times more likely to be uninsured compared with Blacks. In addition, the authors observed lower median of length of stay in the Medicaid category among Hispanics. These results can be explained by aggressive case management, sociocultural barriers, or discriminatory practices, both intentional and unintentional

Random Regression Models Based On The Elliptically Contoured Distribution Assumptions With Applications To Longitudinal Data

We generalize Lyles et al.’s (2000) random regression models for longitudinal data, accounting for both undetectable values and informative drop-outs in the distribution assumptions. Our models are constructed on the generalized multivariate theory which is based on the Elliptically Contoured Distribution (ECD). The estimation of the fixed parameters in the random regression models are invariant under the normal or the ECD assumptions. For the Human Immunodeficiency Virus Epidemiology Research Study data, ECD models fit the data better than classical normal models according to the Akaike (1974) Information Criterion. We also note that both univariate distributions of the random intercept and random slope and their joint distribution are non-normal short-tailed ECDs, and that the error term is distributed as a non-normal long-tailed ECD if we don’t use the low undetectable limit or half of it to replace the undetectable values. Instead, we use the ECD cumulative distribution function to calculate the contribution to the likelihood due to the undetectable values

Disparities in self-reported activities of daily living and instrumental activities of daily living disability among Asian American subgroups in the United States: Results from the National Health Interview Survey 2001-2003

Background The purpose of this study was to compare disability and functional limitations among elderly Asian American subgroups using datasets from the National Health Interview Survey 2001−2003. Methods This retrospective cross-sectional study analyzed whether activities of daily living (ADL) and instrumental ADL (IADL) disabilities were different among Asian American subgroups in the United States using data retrieved from the 2001−2003 National Health Interview Survey. For comparing all Asian American subgroups, χ2 analysis was applied for the bivariate comparisons. Results Rates of 7.1% and 12.2% for ADL and IADL disability, respectively, within Asian American group were found. The elder Chinese subgroup accounted for the highest ADL and IADL disability (11.6% and 17.3%, respectively, p \u3c .05). Being female, not married, and older was associated with higher ADL and IADL disability (p \u3c .05). Conclusions The findings of the study highlight the intergroup variability among the elder Asian American subpopulations

Uncompensated Care Cost: A Pilot Study Using Hospitals in a Texas County

The financial ramifications of uncompensated care cost (UCC) on the healthcare industry have been difficult to quantify. With the lack of a standardized definition of uncompensated care and the need to account for the uninsured, indigent, and immigrant populations, the authors identified $190 million of UCC from Southwestern border hospitals for emergency room treatment of undocumented immigrants and$934 million of uncompensated care charges for 23 hospitals in a Texas county, which translated to $353 million of UCC. Although lawmakers passed the Medicare Prescription Drug Improvement and Modernization Act (2003) to address the growing imbalance, the shortfall of funds highlights the growing crisis and need for policy intervention

Hypertabastic survival model

A new two-parameter probability distribution called hypertabastic is introduced to model the survival or time-to-event data. A simulation study was carried out to evaluate the performance of the hypertabastic distribution in comparison with popular distributions. We then demonstrate the application of the hypertabastic survival model by applying it to data from two motivating studies. The first one demonstrates the proportional hazards version of the model by applying it to a data set from multiple myeloma study. The second one demonstrates an accelerated failure time version of the model by applying it to data from a randomized study of glioma patients who underwent radiotherapy treatment with and without radiosensitizer misonidazole. Based on the results from the simulation study and two applications, the proposed model shows to be a flexible and promising alternative to practitioners in this field

Disparities in ADL and IADL Disabilities among Elders of Hispanic Subgroups in the United States: Results from the National Health Interview Survey 2001-2003

The authors compared disability and functional limitation among elder Hispanic subgroups by using data from the 2001-2003 National Health Interview Survey (National Center for Health Statistics 2008a). The authors applied chi-square analysis for bivariate comparisons and used multiple logistic regression analyses for making comparisons, estimating odds ratios, and predicting disabilities. Results revealed a 21.4% rate of disability of any type in Hispanics. Puerto Ricans reported the highest rates of Activity of Daily Living (ADL) and Instrumental Activity of Daily Living (IADL) disabilities compared with other Hispanic subgroups (Mexicans, Cubans, Central and South Americans) and reported a higher rate than did Blacks. Cubans showed the lowest rate of IADL and any disability among Hispanics and a lower rate than did Whites. These findings highlight the high rates of intragroup variability among the U. S. Hispanic population. Among seniors, ADLs and IADLs were significant predictors of admission to nursing homes and use of paid home care, physician services, and palliative care