• Factors associated with hospitalization in kidney transplant patients

      Brosch, Laura Ruse; Waltz, Carolyn Feher (1998)
      The goal of kidney transplantation is to restore patients' physical function and decrease their dependence upon medical services. Rehospitalization following kidney transplant surgery is a recurrent and costly event that detracts from the ultimate aims of the intervention. The purposes of this retrospective cohort study were to: (1) estimate the rate of rehospitalization for kidney transplant recipients during 90 days following transplantation; (2) identify the reasons for readmission; and (3) identify patient-specific factors, identifiable at time of discharge, that are associated with the likelihood of rehospitalization. Twenty-two demographic and clinical factors were examined in a consecutive series of 300 patients who received kidney transplants between March 1995 and February 1997. The mean age of patients was 46.9 years (SD = 12.59). The median length of initial hospital was 9 days(IQ range = 7-15). One hundred sixty-one patients (53.7%) experienced 267 readmissions during the first 90 days following transplant surgery. Readmissions were for infection (28.8%); acute rejection (27.3%); perinephric/ureteral problems (13%) and fluid and electrolyte imbalances (7.9%). The length of initial hospital stay (median = 14 days) was longer for recipients of older kidneys (>=60 years of age) versus younger kidneys (1-59 years of age) (median = 9 days) (p =.001). The length of initial hospitalization for patients who experienced delayed graft function (median = 17.0 days) exceeded the length of stay for patients who did not (median = 8.0 days) (p < .0001). The Behavioral Model of Health Services Use provided the conceptual framework for this study. Eleven of 22 patient-specific factors were significant in univariate logistic regression and subsequently analyzed in a multivariate logistic regression model. Donor age (OR 1.2, p =.025) and delayed graft function (OR 2.32, p =.008) were significantly associated with the likelihood of rehospitalization. Charlson comorbidity score, donor/recipient CMV status, HLA-mismatch, donor source, immunosuppression, length of initial hospital stay, discharge disposition, and location of residence were not sufficiently associated with readmission to enter the model. Further research is needed to identify the patient and treatment factors associated with readmission in the early posttransplant period.
    • Mechanism of hippocampal neuron death in the trisomy 16 mouse: Failure of BDNF signaling

      Dorsey, Susan Grace; Krueger, Bruce K.; Waltz, Carolyn Feher (2001)
      Down syndrome (DS; trisomy 21) is the most common genetic cause of mental retardation, affecting about one in every 800 individuals. About 60% of the genes on human chromosome 21 are present on mouse chromosome 16 and mouse trisomy 16 (Ts16) has been studied as a potential model for DS. Cultured hippocampal neurons from embryonic Ts16 mice undergo accelerated death by apoptosis in vitro compared with neurons from Euploid littermates. The purpose of this study was to determine the molecular mechanism underlying this accelerated death. Brain-derived Neurotrophic Factor (BDNF), acting through its receptor, trkB, is a well-described autocrine survival factor for hippocampal neurons. BDNF binding to trkB initiates receptor dimerization, autophosphorylation, and activation of several signaling pathways, including AKT and ERK, two signal transduction molecules whose activation by phosphorylation promotes cell survival. To test whether BDNF promoted autocrine survival in Euploid and Ts16 neuronal cultures, endogenous BDNF was removed from the culture medium using a trkB-IgG fusion protein. In the absence of BDNF, Euploid survival was decreased two- to three-fold, similar to control Ts16 survival levels. Survival of the Ts16 neurons was not affected by the removal of BDNF, indicating an absence of autocrine survival signaling by BDNF. Moreover, unlike Euploid neurons, BDNF did not prevent death induced by serum supplement withdrawal in Ts16 neurons. Both Euploid and Ts16 neurons express full-length, catalytically-active trkB, however Ts16 neurons over-express a truncated, kinase-inactive isoform of trkB, which could act as a dominant negative inhibitor of survival signaling. To test whether the over-expression of truncated trkB in Ts16 neurons was the cause of their inability to respond to BDNF, Ts16 neurons were infected with replication-incompetent adenoviruses containing DNA for full-length trkB. The over-expression of full-length trkB in Ts16 neurons completely restored BDNF-mediated survival signaling. In parallel experiments, the over-expression of truncated trkB in Euploid neurons abolished their responsiveness to BDNF, rendering them indistinguishable from Ts16 control neurons. Thus, Ts16 neurons have a selective BDNF survival defect, probably caused by excess truncated trkB, which can be corrected by increasing the levels of full-length trkB.
    • A model of the relationships between health status and satisfaction with care delivery outcomes and health care need and use

      Parker, Ruth Rominger; Waltz, Carolyn Feher; Johantgen, Mary E. (2000)
      Guided by the Behavioral Model of Health Services Use (Andersen and Davidson, 1996), this existing data study tested the influence of population characteristics (predisposing, enabling, and need) and health care use on the outcomes of satisfaction with care delivery and health status after hospital discharge. A descriptive, cross-sectional design was employed to examine outcomes at two to four weeks after discharge from a single academic medical center. Study methodology involved a secondary analysis of survey (satisfaction and health status) and administrative data for a sample of 804 adult, medical-surgical patients discharged home after their acute care stay. The analytic approach was structural equation modeling using Amos. The hypothesized model had an adequate fit with the data; however, it provided minimal explanation of the relationships of health care need and use and predisposing/enabling factors with the outcomes of satisfaction or health status. Of the health care need variables, only transfer status had a significant influence on one of the outcome variables--physical health. Current health care use was found to have no significant relationships with either health status or satisfaction. However, 'past' health care use (defined as the number of hospitalizations the year prior to the current hospital stay) did have a significant influence on both satisfaction and physical health. Of the predisposing characteristics only marital status significantly predicted satisfaction with care delivery. Significant relationships were found between age and mental health and employment with both physical and mental health. Examination of relationships among the outcome variables revealed that satisfaction with care delivery was more strongly associated with physical than mental health in this population. The largest effects with both physical and mental health were seen with nursing care and overall satisfaction. Study limitations which may have contributed to the lack of significant relationships included the absence of baseline health assessment and truncated administrative data, the last of which may have hampered the assessment of both comorbidities and complications. Implications for clinical practice, theory development and future research are proposed.
    • Translation and validation of the California Critical Thinking Dispositions Inventory

      Yeh, Mei-Ling; Waltz, Carolyn Feher (1996)
      The California Critical Thinking Dispositions Inventory (CCTDI) developed by Facione and Facione in 1992 is designed to measure critical thinking dispositions. This 75-item instrument includes seven major subscales: truth-seeking, open-mindedness, analyticity, systematicity, inquisitiveness, self-confidence and maturity. The purpose of this methodological study was to: (1) translate the CCTDI from English to Chinese; (2) ascertain the reliability and validity of the Chinese CCTDI; and (3) assess psychometric equivalencies across Chinese and English versions of the CCTDI. The conceptualization of critical thinking includes two dimensions: cognitive skills and affective dispositions. Personal factors, academic achievement, knowledge base, and environmental factors are thought to be related to each dimension. Based on translation theory, the comparative study goal precisely matched with the strategy of decentered translation. The CCTDI was translated in multiple stages and backtranslated by a panel of bilingual experts. To ascertain content validity for the Chinese CCTDI two Chinese experts rated the item-objective relevancy. The CVIs ranged from .50 to .80, with an overall CVI of .85. To ascertain test-retest reliability, 40 Chinese undergraduate nursing students completed the Chinese CCTDI on two separate occasions. The Pearson r ranged from .33 to .79, with an overall correlation of .79. Evidence for stability of the truth-seeking, open-mindedness, and self-confidence subscales existed. To ascertain internal consistency reliability and construct validity, monolingual samples of 214 and 196 undergraduate nursing students were obtained from Taiwan and the United States, respectively. For the Chinese CCTDI, subscale alphas ranged from .34 to .73, with an overall alpha of .71. For the English version, subscale alphas ranging from .52 to .73 and an overall alpha of .71 were obtained. Alphas were below .70 for the subscales of the Chinese version except for inquisitiveness. A confirmatory factor analysis with LISREL 8 was used to determine construct validity for the Chinese CCTDI. Evidence for construct validity existed for the truth-seeking, open-mindedness, systematicity, and maturity subscales. After allowing some error covariances to exist and deleting three items, evidence for construct validity existed for the remaining subscales. The results of the psychometric equivalencies across the Chinese and English CCTDI showed similarity for content validity and reliability for inquisitiveness. In terms of multisample analysis, there were equal forms across all subscales of the two versions. Consequently, although translation adequacy of the Chinese CCTDI needs to improve, there is evidence that it is useful for evaluating critical thinking dispositions.