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PubMedDate not supplied

Reciprocity for patients with head and neck cancer participating in an instrument development project.

PURPOSE/OBJECTIVES: To examine reciprocity (i.e., a mutual exchange of benefit) in study participation via a thematic analysis of field notes on study participation from a parent psychometric study. DESIGN: Qualitative. SETTING: Head and neck surgery clinic in an urban tertiary hospital. SAMPLE: Seven patients with head and neck cancer recruited to participate in an instrument development project. METHODS: Symbolic interactionism was employed to frame the examination of field notes from observations and interactions with patients, as well as participant notes accompanying returned retest questionnaires. Analysis relied on the constant comparative technique at the levels of open and axial coding. MAIN RESEARCH VARIABLES: Participation in an instrument development project. FINDINGS: Four content themes emerged in the analysis: Willingness to Help, Reassurance That the Deficits Patients Experience Are Common, Participation Provides Social Contact, and Confirmation of Clinically Significant Findings. A process theme, Unveiling the Experience, integrated the content themes in relation to participation itself. The role of the study nurse appears to be pivotal in this process. CONCLUSIONS: A notion of reciprocity in research participation is apparent. The role of the study nurse is an important element in the process of reciprocity. This role should be explored to enhance study participation. IMPLICATIONS FOR NURSING: Implications, particularly for clinical trial nurses, include recasting the benefits of participating in research, better addressing preparation for patients scheduled to receive treatment for head and neck cancer, and exploring and enhancing the role of the study nurse.

Clinical Nursing Research↗
PubMed2003

Focal length variability and protein leakage as tools for measuring photooxidative damage to the lens.

Hypericin is the ingredient used to standardize the popular over-the-counter antidepressant medication St. John's Wort. Because hypericin readily produces singlet oxygen and other excited state intermediates, it is a very efficient phototoxic agent in the eye that can potentially induce the development of the cataract photooxidative mechanism. Hypericin absorbs in the UV and visible ranges, binds to the lens crystallins (alpha, beta and gamma) and damages these proteins through a photooxidative mechanism. Effects were measured previously using fluorescence, UV and mass spectrometry. We report here two additional methods to monitor lens damage: (1) measuring focal length variability using a ScanTox instrument and (2) measuring protein leakage from the damaged lens. Because nonenzymic glycation results in free radical production, we chose to use elevated glucose concentrations as a convenient model for studying oxidative stress. To compare and contrast photooxidative damage against oxidative damage to the lens, we also measured the focal length variability and protein leakage induced by the presence of elevated glucose concentrations. We found that the total accumulated protein leakage was positively correlated (r = 0.9) with variability in focal length. Lenses treated with hypericin and irradiated with UVB had an increase in focal length variability as compared with the lenses that were only UVB-irradiated. Lenses without UVB irradiation had much lower focal length variability than irradiated lenses. For non-hypericin-treated lenses, UVB-irradiated lenses had a larger variability (4.58 mm) than the unirradiated lenses (1.78 mm). The lenses incubated in elevated glucose concentrations had a focal length variability (3.23 mm) equivalent to that of the unirradiated hypericin-treated lenses (3.54 mm). We conclude that photooxidative damage by hypericin results in changes in the optical properties of the lens, protein leakage and finally cataract formation. In contrast to this, high concentrations of glucose induced protein leakage but not changes in optical properties or the opacity associated with a cataract. This work provides further evidence that people should protect their eyes from intense sunlight when taking St. John's Wort.

Animals↗
PubMed1992

Weighting functions and parameter resolvability for oxygenation data subject to error in the independent variable.

Parameter resolvability and bias has been investigated for weighted nonlinear regression of data where the independent variable is subject to instrumental uncertainty. The specific example of cooperative oxygenation of hemoglobin was studied, where fractional saturation is determined spectrophotometrically and the oxygen activity is measured with a Clark polarographic electrode. For this system the instrumental uncertainty in the oxygen electrode was measured directly and the influence of the uncertainties on resolution of oxygen binding parameters was determined by Monte Carlo simulations. Four weighting functions were tested for their ability to minimize parameter uncertainty and bias: (1) uniform weighting; (2) "propagated weighting" whereby uncertainties in the independent variable are propagated into and added to uncertainties of the dependent variable; (3) Hill plot transform, or "end weighting"; and (4) maximum likelihood analysis, where deviations between fitting function and data are minimized as weighted horizontal and vertical distance vectors. Results of the Monte Carlo simulations favor the use of either uniform weighting, propagated weighting, or maximum likelihood weighting methods. Use of the Hill transform as a weighting function produced poorer parameter resolvability and inaccurate representation of the data in general. Bias error was negligible for all weighting functions.

Electrodes↗
PubMed2000

In vitro flexibility of an experimental pedicle screw and plate instrumentation system on the porcine lumbar spine.

The positive correlation between spinal construct stiffness and fusion rate has led to the use of increasingly rigid surgical spinal instrumentation systems. Unfortunately, however, these rigid systems have also been correlated with sub-optimal fusion quality measures. To date, in vivo studies to explore these relationships have involved the use of different implants and surgical procedures to influence the biomechanical environment at the fusion site. In order to avoid these confounding variables, a novel experimental instrumentation system has been developed which is capable of independently controlling spinal construct flexibility (inverse of stiffness). In the present study, this experimental pedicle screw and plate system was subjected to rigorous pure moment flexibility testing in flexion-extension and lateral bending using an in vitro porcine lumbar spine model. Analysis of the data showed that the system provided a reproducible, stepwise-modulated spinal construct flexibility as measured by neutral zone flexibility, laxity angle and range of motion parameters. Differences in flexibility were most evident using the neutral zone parameters (neutral zone flexibility and laxity angle). This is of particular interest given that the clinical instability of a spinal segment may be related to its behaviour within the neutral zone. This information will ultimately guide the design of improved human spinal instrumentation systems.

Animals↗
PubMed1984

Effects of brain renin-angiotensin on cardiovascular function and saline intake in awake dogs.

Initial studies were undertaken to investigate the effects of prolonged administration of angiotensin II (AII), 1 micrograms twice daily, via the lateral ventricles to mongrel dogs on arterial blood pressure and to determine if sodium intake was essential for the development of hypertension. Increasing AII levels in the cerebrospinal fluid for a prolonged period of time produced a sustained hypertensive state only in those dogs in which the daily intake of sodium was increased. The hypertension appeared to be due to an increase in total peripheral resistance. Central administration of AII increased both fluid intake and urine output. In order to assess the hemodynamic effects of increasing endogenous brain AII, renin was injected in doses of 0.025, 0.05, 0.1 and 0.3 units (from porcine kidney) into the lateral ventricles of chronically instrumented awake dogs. Hemodynamic variables were recorded prior to and one and 2 h after the central administration of renin. Renin produced a dose-dependent increase in mean arterial pressure with no significant change in heart rate or carotid, coronary and renal blood flow velocities. Chronic intraventricular administration of renin, 0.15 units twice daily to awake instrumented dogs receiving saline as the drinking fluid, markedly increased the daily intake of saline and increased diastolic and systolic blood pressure without increasing heart rate or carotid, coronary or renal blood flow velocities. There appears to be a direct significant relationship between the increase in mean blood pressure due to the intraventricular administration of renin and the volume of saline consumed.

Angiotensin II↗
PubMed2004

Sleep variables in anorexia nervosa: evolution with weight restoration.

OBJECTIVE: Studies on sleep patterns in anorexia nervosa (AN) have yielded inconsistent results. Therefore, we have studied the evolution of subjective and objective sleep characteristics in AN patients before and after weight restoration. METHOD: Thirty-four severely underweight AN inpatients of the restrictive subtype had a polysomnographic sleep registration at the time of admission and after weight restoration. Subjective sleep quality was also measured with self-report instruments. RESULTS: Objective sleep variables did not change with weight restoration, whereas subjective quality of sleep did improve. Percentage of underweight at admission and amount of slow wave sleep were predictors of the length of time required for weight restoration. DISCUSSION: The finding that weight restoration does not affect polysomnographic sleep variables in AN patients seems to contradict previous studies.

Adult↗
PubMed1999

Evaluation of the self-rating of the effects of alcohol form in Asian Americans with aldehyde dehydrogenase polymorphisms.

OBJECTIVE: In order to easily assess individual differences in response to alcohol, the Self-Rating of the Effects of Alcohol (SRE) form was recently developed and its psychometric properties tested in primarily white subjects. This study aimed to further evaluate the SRE in a population known to have genetically mediated variability in response to alcohol and risk for alcoholism, Asian Americans with ALDH2 polymorphisms. METHOD: Men and women of Chinese, Japanese or Korean heritage between the ages of 21 and 26 years (N = 156) completed the SRE and a blood sample was drawn for genotyping at the ALDH2 locus. RESULTS: SRE results were available from 137 (78 female) subjects. With the effects of gender, body weight, frequency of recent drinking and quantity of recent drinking controlled, ALDH2 genotype still accounted for a significant amount of variability in SRE score in this Asian-American sample. Evaluation of SRE scores 4.5 or higher indicated that a low response to alcohol was associated with ALDH2*1/2*1 genotype, male gender and Korean heritage, all factors associated with increased risk for alcoholism. CONCLUSIONS: These results provide additional support for the SRE as a valid instrument for assessing individual variability in response to alcohol and as a useful measure for identifying individuals at relatively increased or decreased risk for alcoholism based on level of reaction to alcohol.

Adult↗
PubMed2000

[Standardized documentation system for the complementary sector of psychiatric care. Development and trial in Saxony].

The necessity for a standardized documentation system for the complementary sector of psychiatric care is pointed out, and the goals and requirements to be met are debated. The test-version of such a documentation system (abbrev. BADO-K) is shown. It consists of modules for the assessment of client-centered data, and for the documentation of the treatment process in various facilities. Furthermore, a module of questionnaires and instruments for assessing outcome variables (e.g. quality of life) is integrated. The principles for using the paper-pencil-version and the EDP-version are outlined and discussed with regard to the legal regulations concerning the protection of personal data. Finally, possibilities and limitations of the presented documentation system are discussed. It is argued that the BADO-K is an useful instrument for evaluating the process and outcome of community psychiatric care.

Community Mental Health Services↗
PubMed1992

A model for measuring the implementation of community support programs: results from three sites.

We present and test a model for measuring the implementation of Community Support Programs (CSPs) for persons with severe mental illnesses. The model is intended to facilitate the description and replication of these programs and the future study of their critical ingredients. The model defines important implementation variables in seven areas of program functioning; we then suggest instruments to measure each of these variables. Results of a study examining the application of the model and measures to three conceptually distinct CSPs illustrate the utility of the model and measures for implementation analysis of CSPs. Importantly, findings revealed that a priori hypotheses about how the programs were expected to differ on the implementation variables were largely supported.

Adolescent↗
PubMed2002

Does prospective payment really contain nursing home costs?

OBJECTIVE: To examine whether nursing homes would behave more efficiently, without compromising their quality of care, under prospective payment. DATA SOURCES: Four data sets for 1994: the Skilled Nursing Facility Minimum Data Set, the Online Survey Certification and Reporting System file, the Area Resource File, and the Hospital Wage Indices File. A national sample of 4,635 nursing homes is included in the analysis. STUDY DESIGN: Using a modified hybrid functional form to estimate nursing home costs, we distinguish our study from previous research by controlling for quality differences (related to both care and life) and addressing the issues of output and quality endogeneity, as well as using more recent national data. Factor analysis was used to operationalize quality variables. To address the endogeneity problems, instrumental measures were created for nursing home output and quality variables. PRINCIPAL FINDINGS: Nursing homes in states using prospective payment systems do not have lower costs than their counterpart facilities under retrospective cost-based payment systems, after quality differences among facilities are controlled for and the endogeneity problem of quality variables is addressed. CONCLUSIONS: The effects of prospective payment on nursing home cost reduction may be through quality cuts, rather than cost efficiency. If nursing home payments under prospective payment systems are not adjusted for quality, nursing homes may respond by cutting their quality levels, rather than controlling costs. Future outcomes research may provide useful insights into the adjustment of quality in the design of prospective payment for nursing home care.

Cost Control↗
PubMed1995

Personality and performance of preclinical medical students.

This study deals with personality variables of medical students in relation to their academic success in the preclinical stage. One hundred and one students completed the 16PF Questionnaire at the beginning of their medical course and the scores were analysed in relation to their marks obtained at the end of the 2-year preclinical stage. This study shows that the 16PF Questionnaire can be a useful instrument for identifying personality variables in candidates who are likely to have academic problems and those who are likely to do well in the preclinical stage of a medical course. Students of urban origin and the eldest in the family performed better in their preclinical years. Performance was not related to sex, ethnic group, family size of entrance qualification into medicine. Personality variables of being enthusiastic, venturesome, self-opinionated, imaginative, experimenting, resourceful and driven correlate positively with performance, whereas being self-assured has negative correlation. Problem students were more reserved, emotionally less stable and more apprehensive than non-problem students.

Adult↗
PubMed1997

The social networks of older schizophrenia patients. Clinical Research Center on Late Life Psychosis Research Group.

There is a paucity of research that examines the role of family members and friends in the lives of older schizophrenia patients. This study compared 66 middle-aged and elderly outpatients with 31 normal comparison subjects. Five dimensions of social network were assessed: (a) family composition, geographic proximity, and frequency of contact; (b) instrumental support; (c) emotional support and interpersonal difficulties; (d) role of friends; and (e) use of formal service providers as sources of support and assistance. As compared with normal subjects, the schizophrenia patients were less likely to be married, less likely to have children, more likely to live alone, and had fewer friendships. The patients were, however, similar to comparison subjects on the following family-relationship variables: frequency of contact, instrumental support received, presence of a family confidant, and extent of interpersonal difficulties. These findings do not support the stereotype of older schizophrenia patients as being estranged from family members. The need for developing interventions that use key family members to interface with service providers and to monitor treatment compliance and continuity of care is discussed.

Age Factors↗
PubMed1993

Effects of propofol and thiopental on maternal and fetal cardiovascular and acid-base variables in the pregnant ewe.

BACKGROUND: The effects of propofol on uterine blood flow are not understood well. This is a relatively new agent that is finding increased use for nonobstetric surgical procedures during pregnancy and induction of anesthesia for cesarean section. METHODS: The effects of induction and maintenance of anesthesia with propofol were studied on maternal and fetal cardiovascular and acid-base variables in a chronically instrumented pregnant sheep model. Anesthesia was induced with a 2 mg/kg bolus of propofol and maintained with of one of three continuous infusions: 150, 300, and 450 micrograms.kg-1 x min-1. The control group received thiopental for induction, and anesthesia was maintained with isoflurane. RESULTS: The use of propofol did not adversely affect maternal or fetal mean arterial pressure, heart rate, or base excess, fetal heart rate variability, or uterine blood flow. Uterine blood flow transiently decreased during induction and intubation with thiopental but remained stable during induction with propofol. However, administration of succinylcholine for intubation in the presence of propofol resulted in a transient, but severe, maternal bradycardia. Continuous infusion of 300 micrograms.kg-1.min-1 of propofol appeared to provide satisfactory anesthesia in the ewe. CONCLUSIONS: Assuming the applicability of ovine data to humans, these findings suggest that induction and maintenance of anesthesia with propofol and 50% nitrous oxide in oxygen has no adverse fetal effects but warrants caution because of the potential risk of severe maternal bradycardia during induction of anesthesia using the combination of propofol and succinylcholine.

Acid-Base Equilibrium↗
PubMed2006

A preliminary validation of a new measure of occupational health and safety.

INTRODUCTION: This article describes the validation of an instrument designed to conduct an Occupational Health and Safety (OHS) self-diagnosis using workers observations of tangible facts and actions in the workplace. The instrument puts the emphasis on observable factors that make it possible to act proactively before accidents actually occur. METHOD: Three companies were recruited from the printing sector in Québec based on their OHS performance (low, medium, and high), their interest in the project, and their availability. The master sample was composed of 269 people. Partial least squares (PLS) and vanishing tetrad analyses were used to study the behavior of the formative scales developed. RESULTS: The results indicate that partial revision of the instrument will be necessary to reach a fully satisfying level of validity. With regards to the statistical approach adopted, the use of a macro called CTA-SAS 2.0 developed by Bollen and Ting [Bollen, K.A., & Ting, K.-F. (1993). Confirmatory tetrad analysis. In P.V. Marsden (Ed.), Social methodology.Vol.23 (pp.147-176). Cambridge, MA: Blackwell, 23] has proven to be effective in providing a suitable statistical treatment of the latent formative variables on which our instrument's development is based. CONCLUSION: The results suggest that the instrument appears to be relatively robust and appropriate to diagnose OHS leading measures. IMPACT ON INDUSTRY: In the long run, this instrument will make it possible for companies to draw a more refined picture of OHS evolution, even in the absence of occupational injuries.

Accidents, Occupational↗
PubMed2001

Compliance with therapy in patients with chronic hepatitis C: associations with psychiatric symptoms, interpersonal problems, and mode of acquisition.

Tolerance of interferon-a therapy for hepatitis C is often poor and medication is expensive. Compliance with diagnostic procedures and, even more important, with medical treatment is obviously critical to minimize the rate of dropouts and to maximize cost efficiency. Moreover, a good concordance with scheduled follow-ups is important for early recognition and treatment of interferon-associated side effects. Therefore, we investigated psychiatric symptoms, interpersonal problems, different modes of acquisition, and sociodemographic factors in HCV-infected patients as possible predictor variables of good versus poor compliance. In a longitudinal study, 74 patients with chronic hepatitis C (CHC) who fulfilled the criteria for treatment with interferon (IFN)-alpha-2b with or without ribavirin were investigated prospectively to identify those at risk for poor compliance during IFN medication. To assess predictive factors, we used both IIP-C (Inventory of Interpersonal Problems) and SCL-90-R (Symptom Check List 90 Items Revised) as psychometric instruments. Sociodemographic and somatic variables as well as compliance during IFN therapy were also evaluated. Poor compliance before or during medication was demonstrated by 23% (N = 17) of HCV patients. Sociodemographic factors and mode of acquisition, particularly former intravenous drug (IVD) abuse were not significantly linked with compliance. Logistic regression analysis demonstrated that the subgroup of patients with compliance problems was best identified by both pretherapeutic psychiatric symptoms and interpersonal problems. Predictive value was best and significant for anger-hostility (P = 0.009), intrusive (P = 0.014), depression (P = 0.015), and phobic anxiety (P = 0.049). Adopting this statistical prediction model, sensitivity was 47.1%, but specificity reached 98.3%. In total, 86.5% of cases were classified correctly. In situations of unclear indication for IFN therapy, psychological variables assessment of before the beginning of treatment may represent an additional decision-making factor.

Adolescent↗
PubMed2002

Relationship of sleep hygiene awareness, sleep hygiene practices, and sleep quality in university students.

College students are known for their variable sleep schedules. Such schedules, along with other common student practices (e.g., alcohol and caffeine consumption), are associated with poor sleep hygiene. Researchers have demonstrated in clinical populations that improving sleep hygiene knowledge and practices is an effective treatment for insomnia. However, researchers who have examined relationships between sleep hygiene and practices in nonclinical samples and overall sleep quality have produced inconsistent findings, perhaps because of questionable measures. In this study, the authors used psychometrically sound instruments to examine these variables and to counter the shortcomings in previous investigations. Their findings suggest that knowledge of sleep hygiene is related to sleep practices, which, in turn, is related to overall sleep quality. The data from their regression modeling indicated that variable sleep schedules, going to bed thirsty, environmental noise, and worrying while falling asleep contribute to poor sleep quality.

Adult↗
PubMed2006

Performance of a decision rule to predict need for computed tomography among children with blunt head trauma.

OBJECTIVE: To assess the ability of the NEXUS II head trauma decision instrument to identify patients with clinically important intracranial injury (ICI) from among children with blunt head trauma. METHODS: An analysis was conducted of the pediatric cohort involved in the derivation set of National Emergency X-Radiography Utilization Study II (NEXUS II), a prospective, observational, multicenter study of all patients who had blunt head trauma and underwent cranial computed tomography (CT) imaging at 1 of 21 emergency departments. We determined the test performance characteristics of the 8-variable NEXUS II decision instrument, derived from the entire NEXUS II cohort, in the pediatric cohort (0-18 years of age), as well as in the very young children (<3 years). Clinically important ICI was defined as ICI that required neurosurgical intervention (craniotomy, intracranial pressure monitoring, or mechanical ventilation) or was likely to be associated with significant long-term neurologic impairment. RESULTS: NEXUS II enrolled 1666 children, 138 (8.3%) of whom had clinically important ICI. The decision instrument correctly identified 136 of the 138 cases and classified 230 as low risk. A total of 309 children were younger than 3 years, among whom 25 had ICI. The decision instrument identified all 25 cases of clinically important ICI in this subgroup. CONCLUSIONS: The decision instrument derived in the large NEXUS II cohort performed with similarly high sensitivity among the subgroup of children who were included in this study. Clinically important ICI were rare in children who did not exhibit at least 1 of the NEXUS II risk criteria.

Adolescent↗
PubMed2005

Vertebral rotation and thoracic torsion in adolescent idiopathic scoliosis: what is the best radiographic correlate?

BACKGROUND: As a result of the increased appreciation of the three-dimensional nature of scoliosis and modern spinal instrumentation's improved corrective capabilities, there has been renewed interest in the correction and measurement of vertebral rotation. Computed tomography (CT), the gold standard for accuracy, is limited in its clinical utility owing to cost, radiation exposure, and the effects of postural changes on scoliosis curves and vertebral rotation. Consequently, the Perdriolle and Nash-Moe techniques remain the standard measurements for providing a reasonable estimate of pre- and postoperative vertebral rotation because of their simplicity. However, these techniques have considerable interobserver variability, and pedicle screw instrumentation obscures the landmarks necessary for utilizing these techniques for postoperative vertebral rotation assessment. The purpose of the present study was to assess the utility of alternate radiographic measures to assess vertebral rotation and thoracic torsion when compared with conventional measures on pre- and postoperative radiographs and CT evaluation. METHODS: We reviewed the preoperative, immediate postoperative, and final follow-up radiographs, as well as the pre- and postoperative CT scans, of 19 patients (average age 15 years, 6 months) with Lenke 1 curves (average 55 degrees , range 47-66 degrees ), all treated with anterior spinal fusion. Coronal and sagittal Cobb angles as well as vertebral rotation (Perdriolle and Nash-Moe) at the superior uninstrumented, superior instrumented, apical, inferior instrumented, and inferior uninstrumented vertebrae were measured on all films, and vertebral rotation was assessed on the CT scans by a previously described method. Additionally, several measures of thoracic torsion (as a proxy for vertebral rotation and overall deformity improvement) were assessed. These included the rib-vertebral angle difference (RVAD), apical rib hump prominence (RH), apical vertebral body-rib ratio (AVB-R), and apical rib spread difference (ARSD). RESULTS: The postoperative main thoracic curve averaged 26 degrees (range 16-39 degrees , 52% correction) and 29 degrees (range 22-40 degrees , 47% correction) at final follow-up. For apical derotation, the postoperative CT improved from -11.5 degrees to -6.6 degrees and correlated significantly with the Cobb main thoracic curves (42% correction, r = 0.48, P = 0.003). There was weakly positive, but statistically significant, correlation between the pre- and postoperative CT scans and the corresponding Perdriolle and Nash-Moe measures of segmental rotation (r = 0.32-0.40, all P < 0.0001). The RVAD demonstrated poor correlation with the main thoracic curve values and correction, Perdriolle rotation and correction, and CT rotation and correction (r = -0.22-0.37, all P > 0.20). The apical RH demonstrated good correlation with the main thoracic curve (r = 0.65, P < 0.0001), apical Perdriolle rotation (r = 0.57, P < 0.0001), and CT apical rotation (r = 0.53, P = 0.002). We also found moderate correlation between the AVB-R and the main thoracic Cobb, apical Perdriolle, and CT (r = 0.57, 0.59, and 0.49, respectively; all P < 0.005). Similar relationships were found with the ARSD (r = 0.51, 0.47, and 0.43, respectively; all P < 0.02). CONCLUSIONS: The RH, AVB-R, and the ARSD-measures of thoracic torsion-demonstrated moderate to good overall correlation with the main thoracic curve Cobb angles, apical Perdriolle rotation, and apical CT rotation. These should be useful as clinical measures for assessing three-dimensional deformity correction on plane radiographs, especially for the intraoperative evaluation of vertebral derotation and thoracic symmetry restoration.

Adolescent↗