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PubMedDate not supplied

Toward national comparable nurse practitioner data: proposed data elements, rationale, and methods.

Federal funds have supported Nurse Practitioner (NP) education and the establishment of nurse-managed centers. Yet, important questions are raised about the quality and appropriate scope of NP care. Few NP-patient encounters are documented in the largest national surveys of ambulatory care, sponsored by the National Center for Health Statistics, due to sampling frames that are based on physician practices. In addition, these national surveys lack essential outcome indicators, therefore limiting their data to descriptions of patient demographics and practice patterns. Informatics principles are applied to a proposed expansion of the National Ambulatory Medical Care Survey. Its sample would include nurse-managed centers and its variables would include quality outcome and process indicators in standardized language that are nurse-sensitive and that reflect national priorities for action on health care quality. Variables for inclusion in a draft pilot instrument are identified.

Ambulatory Care↗
PubMed2006

Objective real-time measurement of instrument myopia in microscopists under different viewing conditions.

While instrument myopia is known to occur when microscopes are used, little is known about the accommodation response during microscopy, or about the factors which may alter the magnitude of instrument myopia. In addition, there has been no real-time objective measurement of instrument myopia during the microscopy task. Twenty inexperienced subjects and 10 experienced microscopists (average work experience of 4.8 years (SD 3.2 yr)) with mean age of 24.1 years (SD 2.9 yr) and 31.2 years (SD 2.9 yr) respectively were recruited to the study. Instrument myopia was measured using an infrared photorefractor (PowerRefractor) under different viewing conditions and microscope settings (with different forms of refractive error correction, changes in target quality, changes in eyepiece power settings, changes in magnification and changes in illumination of the target). Instrument myopia was greater in inexperienced (1.98 D (SD 0.91 D)) than in experienced (1.38 D (SD 0.75 D)) microscope users. There was no statistically significant change in the level of instrument myopia under the different viewing conditions or different microscope settings, and there were large individual variations. Other factors may play more of a role in determining the degree of instrument myopia during microscopy than the task variables altered here.

Accommodation, Ocular↗
PubMed2001

A comparison of three measures: the time trade-off technique, global health-related quality of life and the SF-36 in dialysis patients.

We investigated the correlation between descriptive and valuational measures of health-related quality of life (HRQL) and assessed determinants affecting these measures. Our suspicion was that there is little similarity in the content of descriptive and valuational measures of HRQL. We thus conducted a cross-sectional observational study of 56 hemodialysis patients. All underwent structured interviews. Dependent variables were patients utilities [time trade-off (TTO)], global rating of HRQL and generic HRQL (SF-36). Independent variables were socioeconomic details, disease severity, comorbidity, symptoms, depression, social support, and laboratory data. The correlation between TTO and global HRQL was -0.33 (P = .0178) and between TTO and the SF-36 physical and mental summary scores -0.16 (P = .2383) and -0.20 (P = .1443), respectively. The regression models for the SF-36 physical and mental summary scores explained 75% and 64% of the variance, and for global HRQL 29% of the variance. The independent variables had no effect on the TTO. This confirmed our suspicion that a qualitative difference exists between TTO and descriptive quality of life tools. The TTO content could not be explained by the variables that entail the content of HRQL instruments.

Adult↗
PubMed2002

Continuous monitoring of myocardial acid-base status during intermittent warm blood cardioplegia.

OBJECTIVE: Intermittent warm blood cardioplegia (IWBC) is a well-established technique for myocardial protection during cardiac operations. According to standardized protocols, IWBC administration is currently performed every 15-20 min regardless of any individual variable and in the absence of any instrumental monitoring. We devised a new system for continuous measurement of the acid-base status of coronary sinus blood for on-line evaluation of myocardial oxygenation during IWBC. METHODS: In 19 patients undergoing cardiac surgery for coronary artery bypass graft and/or valve surgery and receiving IWBC (34-37 degrees C) by antegrade induction (3 min) and retrograde or antegrade maintenance (2 min) every 15 min, continuous monitoring of myocardial oxygenation and acid/base status was performed by means of a multiparameter PO(2), PCO(2), pH, and temperature sensor (Paratrend7 (R), Philips Medical System) inserted into the coronary sinus. RESULTS: Mean cross-clamping time was 76+/-26 min; ischemic time was 13+/-0.2 min. pH decline was not linear, showing an initial fast decline, a point of flexus, and a progressive slow decline. After every ischemic period, the pH adaptation curve showed a complex pattern reaching step-by-step lower minimum levels (7.28+/-0.14 during the first ischemic period, to 7.16+/-0.19 during the third ischemic period - P=0.003). PO(2) decreased rapidly at 90% in 5.0+/-1.2 min after every reperfusion. During ischemia, PCO(2) increased steadily at 1.6+/-0.1 mmHg per minute, with progressively incomplete removal after successive reperfusion, and progressive increase of maximal level (42+/-12 mmHg during the first ischemic period, to 53+/-23 mmHg during the third ischemic period - P=0.05). CONCLUSIONS: Myocardial oxygen, carbon dioxide, and pH show marked changes after repeated IWBC. Myocardial ischemia is not completely reversed by standardized reperfusions, as reflected by steady deterioration of PCO(2) and pH after each reperfusion. Progressive increase of reperfusion durations or direct monitoring of myocardial oxygenation could be advisable in cases of prolonged cross-clamping time.

Acid-Base Equilibrium↗
PubMed1995

5-Bromomethyl fluorescein (5-BMF) for derivatization of carboxyl containing analytes for use with laser-induced fluorescence detection.

PURPOSE: 5-Bromomethyl fluorescein (5-BMF) was evaluated in this work as a pre-column, off-line derivatizing reagent for analytes containing a free carboxyl group. The reagent possessed high molar absorptivity and quantum yield and it's excitation maximum matched the intense 488.0 nm emission line of an argon ion laser. The thermal and photo-stability of the reagent were also suitable for our work. METHODS: A mixture of 5-BMF, palmitic acid, 18-crown-6 and potassium carbonate was reacted at 76 degrees C for one hour. The reaction yield was maximized by a sequential single-factor optimization of the reaction variables. Spectral characterizations were accomplished using conventional instrumentation and detection limits were evaluated using a laboratory constructed laser-induced fluorescence (LIF) detector which was optimized for concentration detection. RESULTS: Two apparent conjugates of palmitic acid were formed under the reaction conditions employed. The conjugate chosen for quantitative purposes was stable at room temperature over 24 hours and possessed high molar absorptivity (128,832 M-1cm-1) and quantum yield (0.82) under basic conditions. The excitation and emission maxima of the conjugate were 500 nm and 523 nm respectively which maintains suitability for argon-ion laser excitation. An argon-ion LIF detector suitable for use with conventional liquid chromatography was constructed. A detection limit of 7.56 x 10(-10)M of palmitic acid was achieved at a signal to noise ratio of three, using the strong 488.0 nm laser emission line and a commercially available flow cell component. This corresponds to 38 femtomoles of palmitic acid on-column. CONCLUSION: The concentration detection limit was superior to literature reports for detection of fatty acids. The mass detection limit provided approximately an order of magnitude improvement over conventional fluorescence. The reagent is potentially useful for analysis of carboxyl containing analytes at low concentrations.

Carboxylic Acids↗
PubMed2002

Ropivacaine 2 mg/mL vs. bupivacaine 1.25 mg/mL with sufentanil using patient-controlled epidural analgesia in labour.

BACKGROUND: In recent studies, minimum local analgesic concentrations have been defined as 0.93 mg/mL for bupivacaine and 1.56 mg/mL for ropivacaine for epidural analgesia for the first stage of labour, resulting in an analgesic potency ratio of 1 : 0.6. In the current study we compared ropivacaine and bupivacaine in a PCEA system (combined with sufentanil) taking this potency ratio into account but administering drug doses providing sufficient analgesia for all stages of labour. METHODS: In a prospective, double-blinded study 114 parturients were randomised to receive either ropivacaine 2 mg/mL with sufentanil 0.75 microg/mL or bupivacaine 1.25 mg/with sufentanil 0.75 microg/mL. After epidural catheter placement, PCEA was available with boluses of 4 mL, a lock-out time of 20 min and no basal infusion rate. We evaluated pain intensity during contractions, sensory and motor function, duration of labour, mode of delivery and neonatal outcome. Consumption of local anaesthetic and opioid drugs and PCEA system variables were recorded. RESULTS: Mean total consumption as well as mean hourly drug consumption was significantly increased in the ropivacaine-sufentanil group. No differences in analgesic quality, sensory or motor blocking potencies or neonatal outcome variables between groups were detected. Frequency of instrumental deliveries was significantly increased in the ropivacaine-sufentanil group. CONCLUSIONS: The results support the findings of previously published studies postulating ropivacaine to be 40-50% less potent for labour epidural analgesia compared to bupivacaine. However, we observed an increased frequency of instrumental deliveries with ropivacaine. To evaluate the clinical relevance of these findings, further investigations are warranted.

Amides↗
PubMed1988

Assessment of methods for measuring social support.

A rapidly expanding literature documents the effects of social support on physical and psychological well-being. Although definitions vary, most include both tangible components (e.g., financial assistance and physical aid) and intangible components (e.g., encouragement and guidance). Social support has been implicated in the mediation of stressful life events, recovery from illness, and increased program adherence. There are many inconsistent findings in the literature, however, and it is difficult to resolve discrepancies because measures of social support vary widely from study to study. To guide in the selection of measurement methods for research and applied work, 23 techniques for assessing social support are reviewed and evaluated. Criteria for favorable evaluation included reliability coefficients greater than .8 and documentation of validity. Correlations between various social support and criterion measures are simulated in order to demonstrate the consequences of choosing a measure with low reliability. Scale developers reported reliability data for 19 of the reviewed measures. Internal consistency coefficients ranged from .31 to .98. Test-retest coefficients ranged from .22 to .96. At least some validity documentation was available for 13 of the scales. Discriminant validity evidence, however, is almost universally absent. Despite psychometric weaknesses and variability among the scales, researchers have several instruments available to them.

Adaptation, Psychological↗
PubMed1989

The 57 mm thermal clearance probe: a non-invasive tool for measuring subcutaneous blood flow.

1. The segmented thermal clearance probe is a non-invasive instrument which measures heat thermal clearance, a variable directly proportional to superficial blood flow, with a depth sensitivity theoretically proportional to the sensor diameter. We compared an 18 mm sensor and a recently developed 57 mm sensor with the reference technique of xenon washout. 2. The theoretical depth sensitivity of the sensors was assessed using Perspex spacers. Ninety-five per cent of sensitivity had been lost at the respective depths of 3.5 mm and 7.1 mm for the 18 mm and 57 mm sensors. 3. A comparison was made between heat thermal clearance reading and 133Xe decay curves using the two probes for 15 min after injection of 133Xe at 2 mm and 6 mm depths in the anterior thigh in 41 subjects. The 57 mm sensor showed similar correlation with xenon washout at 2 mm injection depth (r = 0.89) and 6 mm injection depth (r = 0.86), whereas the 18 mm sensor showed greater correlation at 2 mm (r = 0.92) than at 6 mm (r = 0.62). 4. The 57 mm sensor was compared with xenon washout at 6 mm in eight insulin-treated diabetic subjects. The relationship was similar to that in non-diabetic subjects (r = 0.79), with no significant difference in slope or intercept. 5. It is concluded that the 57 mm thermal clearance probe may be used to study blood flow at the depth of insulin injection (6 mm) in diabetic and non-diabetic subjects.

Adult↗
PubMed1985

[Prediction of therapeutic success in acute neuroleptic treatment: results of an empirical study of 243 inpatient-treated schizophrenic patients].

A study on 243 schizophrenic inpatients treated with neuroleptics was performed. Using standardized rating instruments a large set of potential prediction variables was tested. Several predictors, known from the literature, could be confirmed, also by cross validation according to the split half technique: among others premorbid disturbances of social adjustment, insidious onset of illness, duration of symptoms before admission, intensity of symptoms at admission, duration of previous hospitalisation. The prognostic scale of Strauss and Carpenter, originally developed for long term prognosis, proved as the most relevant predictor. By stepwise multiple regression analyses an optimal combination of five predictors, explaining 30% to 40% outcome variance was found. The latter result is being tested in a prospective study.

Acute Disease↗
PubMed2000

Characterization of indoor particle sources using continuous mass and size monitors.

A comprehensive indoor particle characterization study was conducted in nine Boston-area homes in 1998 in order to characterize sources of PM in indoor environments. State-of-the-art sampling methodologies were used to obtain continuous PM2.5 concentration and size distribution particulate data for both indoor and outdoor air. Study homes, five of which were sampled during two seasons, were monitored over week-long periods. Among other data collected during the extensive monitoring efforts were 24-hr elemental/organic carbon (EC/OC) particulate data as well as semi-continuous air exchange rates and time-activity information. This rich data set shows that indoor particle events tend to be brief, intermittent, and highly variable, thus requiring the use of continuous instrumentation for their characterization. In addition to dramatically increasing indoor PM2.5 concentrations, these data demonstrate that indoor particle events can significantly alter the size distribution and composition of indoor particles. Source event data demonstrate that the impacts of indoor activities are especially pronounced in the ultrafine (da < or = 0.1 micron) and coarse (2.5 < or = da < or = 10 microns) modes. Among the sources of ultrafine particles characterized in this study are indoor ozone/terpene reactions. Furthermore, EC/OC data suggest that organic carbon is a major constituent of particles emitted during indoor source events. Whether exposures to indoor-generated particles, particularly from large short-term peak events, may be associated with adverse health effects will become clearer when biological mechanisms are better known.

Air Pollution, Indoor↗
PubMed2005

The clinical interview and the doctor-patient relationship in telemedicine.

The doctor-patient relationship is one of the most complex interpersonal relationships, in that it involves individuals who are not on the same level, it has not been sought by both individuals, it is emotionally loaded and it requires close mutual co-operation towards a shared goal. A well-managed clinical interview lays the grounds for a good doctor-patient relationship which in turn leads to further advantages. In a classical ambulatory setting the doctor-patient relationship should take into account a number of context variables: physical environment, doctor's clothing and instrumental vs. affective behavior. The classical medical consultation takes place with the doctor and patient facing each other in the same room. Human contact, interaction and communication condition the course and treatment of the illness. This classical setting has been radically changed with the advent of videoconferencing. Video-communication reduces personal contact with the general doctor or specialist. Medical philosophy and the social sciences have often discussed the risk of alienating or "objectifying" the patient. The setting of a videoconferencing interview is completely different as interaction is not direct but occurs via a technological system that enables an unusual form of visual and auditory interaction that may be more or less realistic depending on the technology employed. The growing use of telemedicine and videoconferencing has led to new reflections on the doctor-patient relationship in non-conventional settings and warrants in-depth studies on the dynamics of this form of consultation so as to increase the patients' level of satisfaction in telemedicine. The next step will be to verify experimentally and with adequate tools what the demands of patients are in a videoconferencing setting.

Health Status↗
PubMed1997

Craniofacial parameters during growth from the deciduous to permanent dentition--a longitudinal study.

Data on the dynamics of craniofacial growth, obtained by simple non-invasive measurements, are scarce in comparison with those collected by cephalometric methods. The aim of this study was to measure a number of craniofacial parameters, and to evaluate their changes during transition from the deciduous to the permanent dentition. A sample of 61 subjects (32 boys and 29 girls) were followed longitudinally by annual examination from an initial mean age of 4.7 years to a final mean age of 11.8 years. Conventional anthropometric instruments were employed to measure six craniofacial variables: G-Op, Eu-Eu, Zy-Zy, Go-Go, N-Gn and N-Pr. The data were analysed using basic summary statistics and a longitudinal regression model. A difference between males and females was found for all variables during the study period. During the transition from deciduous to mixed dentition (4.7-7.5 years), the cranial breadth and length (Eu-Eu and G-Op) decreased followed by an increase during the mixed dentition. All other parameters showed a continuous increase, which was highest for the variables defining facial height.

Anthropometry↗
PubMed1998

Predictors of relapse and rehospitalization in schizophrenia and schizoaffective disorder.

In a German multicenter treatment study, 354 patients with schizophrenia and schizoaffective disorder were followed for 2 years. The data collected were taken as a basis for the present predictor study. For the first time, the technique of classification and regression tree (CART) analysis has been employed for this purpose. CART yielded informative data and appeared to be a useful instrument in predictor research. On the outcome variables "relapse" and "rehospitalization," significant predictor variables were found in several areas: neuroleptic treatment, onset and previous course (precipitating factors, first manifestation, hospitalization in the preceding year, suicide attempts), psychopathology (residual type, schizoaffective disorder), social adjustment (marital status, employment, intensity of life, Phillips score), previous life experiences (traumatic experiences and psychiatric or developmental disturbances in childhood), and biology (gender, age). Our investigation confirmed the generally prevalent views regarding the value of neuroleptic treatment, the multifactorial etiology, and the vulnerability stress model of schizophrenia.

Adult↗
PubMedDate not supplied

Alternate models of positive health practices in adolescents.

The purpose of this study was to develop and test two alternate causal models of positive health practices in adolescents, which built on a modification of the original theoretical formulation previously tested in adolescents by Yarcheski and Mahon (1989). The sample consisted of 202 adolescents, aged 15 to 21. In classroom settings they responded to instruments and a demographic data sheet measuring variables in both models (age, gender, self-esteem, social support, and positive health practices), and to additional variables in Model 1 (future time perspective) and Model 2 (perceived health status). Both causal models were tested by the LISREL 7 program. By all indicators used in the study, there was a very good fit of both models with their data, there were no specification errors in either model, and neither model required modification. Visual inspection of the indicators suggested that Model 1 had a slightly better fit than did Model 2 with their respective data. These results suggested that causal models explaining positive health practices should include endogenous variables that share a common orientation, such as those with a psychosocial focus versus those with a health-related focus.

Adolescent↗
PubMed1990

Low-back pain. Factors of value in predicting outcome.

Two separate samples of 50 workers' compensation patients were assessed within 3 to 6 months of their first back injury and were reassessed at a mean of 13.7 months postinjury, at which time work status was also determined. A number of predictors on the first assessment then were correlated with return to work. These predictors included orthopaedic evaluations of severity and prognosis, the number of nonorganic physical signs, Minnesota Multiphasic Personality Inventory (MMPI) scales 1 and 3, age, education, proficiency in English, and the accuracy of patients' understanding of the bases for their medical condition as determined by the Schema Assessment Instrument (SAI). The SAI was the only variable to predict return to work significantly in both samples. These data point to the importance of patients' understanding of their medical condition for their prognosis.

Adult↗
PubMed1993

Electrodermal activity in anxiety disorders.

Forty anxiety patients diagnosed according to DSM-III-R criteria were included: panic disorder (n = 12), agoraphobia (n = 11), generalized anxiety disorder (n = 9), anxiety disorder not otherwise specified (n = 8) and compared with 12 controls. Millon Clinical Multiaxial Inventory and Symptom Checklist-90R symptom and personality scales did not separate the diagnostic groups. Electrodermal activity showed delayed habituation and high spontaneous skin resistance fluctuations in the panic and agoraphobia groups compared with the non-panic groups. The generalized anxiety disorder patients could not be separated from the controls, and the anxiety disorder not otherwise specified patients showed less electrodermal activity than the controls on most variables. In contrast to self-report instruments, electrodermal activity discriminated between diagnostic groups of patients with DSM-III-R anxiety disorders, more specifically between patients with and without panic attacks.

Acoustic Stimulation↗
PubMed1997

Visual assessment of human skin irritation: a sensitive and reproducible tool.

Human volunteer studies of skin irritation have been carried out for decades, both for research and for safety evaluation purposes. For the majority of this time, and consequently for the majority of the studies, assessment of the skin reactions has been made visually. Typical endpoints include erythema, oedema, dryness and scaling, some or all of which would be rated on a simple scale, eg 0, +/-, +, ++, + + +. Such approaches can be criticized as subjective, of poor reproducibility, lacking in sensitivity and highly variable between observers and/or institutions. In consequence, instrumental methods of assessment have been strongly promoted and do indeed offer several advantages, not least their objectivity. However, it is possible to use the human eye, which is a very sensitive tool, to make detailed, accurate and reproducible descriptions of skin irritation reactions. To achieve this, it is necessary to give prolonged and thorough training to each observer. In this paper, 3 examples of human volunteer studies, in which different pairs of trained observers independently carried out double blinded scoring of the irritation reactions, are reported. The grading patterns produced were almost identical; statistical analysis showed that properly trained observers are in fact able to reliably measure a grade of erythema to within +/- 1 on a 10 point scale; 97.6% of scores were within 2 grade points on this scale. These results provide evidence that visual scoring can be sensitive, reliable and reproducible within a testing institution.

Dermatitis, Irritant↗
PubMed2005

Brain SPECT with short focal-length cone-beam collimation.

Single-photon emission-computed tomography (SPECT) imaging of deep brain structures is compromised by loss of photons due to attenuation. We have previously shown that a centrally peaked collimator sensitivity function can compensate for this phenomenon, increasing sensitivity over most of the brain. For dual-head instruments, parallel-hole collimators cannot provide variable sensitivity without simultaneously degrading spatial resolution near the center of the brain; this suggests the use of converging collimators. We have designed collimator pairs for dual-head SPECT systems to increase sensitivity, particularly in the center of the brain, and compared the new collimation approach to existing approaches on the basis of performance in estimating activity concentration of small structures at various locations in the brain. The collimator pairs we evaluated included a cone-beam collimator, for increased sensitivity, and a fan-beam collimator, for data sufficiency. We calculated projections of an ellipsoidal uniform background, with 0.9-cm-radius spherical lesions at several locations in the background. From these, we determined ideal signal-to-noise ratios (SNRCRB) for estimation of activity concentration within the spheres, based on the Cramer-Rao lower bound on variance. We also reconstructed, by an ordered-subset expectation-maximization (OS-EM) procedure, images of this phantom, as well as of the Zubal brain phantom, to allow visual assessment and to ensure that they were free of artifacts. The best of the collimator pairs evaluated comprised a cone-beam collimator with 20 cm focal length, for which the focal point is inside the brain, and a fan-beam collimator with 40 cm focal length. This pair yielded increased SNRCRB, compared to the parallel-parallel pair, throughout the imaging volume. The factor by which SNRCRB increased ranged from 1.1 at the most axially extreme location to 3.5 at the center. The gains in SNRCRB were relatively robust to mismatches between the center of the brain and the center of the imaging volume. Artifact-free reconstructions of simulated data acquired using this pair were obtained. Combining fan-beam and short-focusing cone-beam collimation should greatly improve dual-head brain SPECT imaging, especially for centrally located structures.

Algorithms↗