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[Comparison of 4 skin prick tests to detect immediate hypersensitivity].

AIMS: To diagnostic allergic diseases it's necessary an adequate history, and in vivo or in vitro test, to determine specific IgE. The skin prick test are the best for this, because are more sensitive, economic and quick to do. However there are variability in results with the different instruments to do it (the Morrow-Brown (MB), needle, Prick lancet (L)t Multi-Test (MT), and the Doutip-Test). To consider this instruments how adequate diagnostic proceedings, we should evaluate some characteristics. Because it, our objective was to evaluate precision, sensitivity, specificity and patient preference by each one. METHOD: Prospective study in 20 patients with asthma or allergic rhinitis who comes to the allergy service of Hospital Infantil de México Federico Gómez. We analyzed skin prick test with DT, MB, MT and L on the back surface with histamine in five times and glicerosaline in one. We measured wheel and flare diameters 15 minutes after applications. We consider positive results if medium diameter of wheel was 3 mm or flare 10 mm. Precision was measured by coefficient of variation of wheel with histamine with each instrument. Patient preference was considered in relation to low grade of discomfort with each one. Precision was compared by two- vias varianza analysis. No parametric Friedman test was used to compared patient preference. RESULTS: We studied 20 patients, 40% was females and 60% males. The ages were 10 to 16 years old Promedio wheal histamine diameter was to MB = 5.1 +/- 1.1, L = 6.1 +/- 0.8, DT = 6.7 +/- 0.9, MT = 6.3 +/- 1.5; promedio flare diameter with histamine was to MB: 15.9 +/- 4.2, L: 19.0 +/- 4.8, DT = 21.9 +/- 4.8, MT = 18 +/- 6.9. Sensibility of DT was 100%, L = 99%, MT = 97% and MB 95%. The specificity of MB was 90%, L = 70%, MT = 41.6% and DT 30%. DT coefficient of variation was 15.6%, L: 17.3%, MT = 24.4% and MB 24.6%. CONCLUSIONS: In our study more sensitive device was DT, more specific was MB and more precise was DT. Patients preferred the lancet, because they had less discomfort when used it.

Adolescent↗
PubMed1975

Concordance of multiple assessments of the outcome of schizophrenia. On defining the dependent variable in outcome studies.

Concordance of multiple assessments of the outcome of schizophrenia are examined from (1) concordance of three different assessments of mental status, and (2) concordance of four different dimensions of outcome. Findings are related to the methodological issue of defining the dependent variable in outcome studies. When the assessment instruments were compared, discordance in overall assessment happened because each instrument taps varying aspects of symptomatology, suggesting that outcome is somewhat instrument-related. Although adjustment in mental status is correlated with social adjustment and role performance, a patient's status at follow-up bears little relationship to rate of rehospitalization or to consumer satisfaction with treatment. A differential impact of the same predictor variables on four dimensions of outcome underscores the discordance in multiple assessments. Since treatment outcome is multifaceted and multidertermined, multiple assessments must continue as vital procedures.

Adult↗
PubMed2000

Free-operant performance on variable interval schedules with a linear feedback loop: no evidence for molar sensitivities in rats.

Four experiments examined rats' sensitivity to molar and molecular factors on instrumental schedules of reinforcement. Rats were exposed to a variable interval schedule with a positive feedback loop (VI+), such that faster responding led to a shorter interreinforcement interval. In Experiments 1 and 2, rats responded faster on a variable response (VR) schedule than on either a VI schedule matched for reinforcement rate or a VI+ schedule matched for the feedback function. In Experiment 3, rats responded no differently on a VI schedule than they did on a VI+ schedule with equated rates of reinforcement. In Experiment 4, rats responded faster on a VI+ schedule with an interresponse time requirement yoked to that experienced on a VR schedule, than on a VI+ schedule with the same feedback function as the VR schedule. Taken together these results suggest that rats are more sensitive to the molecular than the molar properties of the schedules.

Animals↗
PubMed2001

Clinical application of a new colonoscope with variable insertion tube rigidity: a pilot study.

BACKGROUND: Colonic loop formation can prolong colonoscopy, increase patient discomfort, and preclude complete examination. A colonoscope with variable insertion tube rigidity may facilitate colonoscopy. Our aim was to determine whether the use of a colonoscope with variable insertion tube rigidity reduces insertion time and improves patient acceptance of colonoscopy. METHODS: Fifty patients were randomly assigned to undergo colonoscopy with a conventional colonoscope or a variable rigidity colonoscope (VRC). Patient acceptance, dosage of medication, use of abdominal pressure, and patient repositioning were assessed. Statistical analysis was performed by the 2-sample Wilcoxon rank sum test and an extension of Fisher exact test. RESULTS: The groups were comparable with respect to age, gender, and medications required during colonoscopy. The cecum was reached in all 25 patients who underwent colonoscopy with the VRC, including 1 patient in whom the cecum was not reached at a previous colonoscopy with a conventional instrument. In the conventional colonoscopy group, the cecum was not reached in 4 patients (2 poor preparation, 2 loop formation). There was no significant difference between the 2 groups with respect to insertion time. In the group that underwent colonoscopy with the variable rigidity instrument, less abdominal pressure was required (p = 0.05), and nursing assessment of patient discomfort was more favorable (p = 0.05). There were no complications and no significant differences in the intubation time to cecum or in repositioning, patient acceptance, or patient assessment of abdominal pain. CONCLUSION: The use of a variable rigidity colonoscope reduced the frequency of abdominal pressure but did not affect intubation time to cecum, repositioning, patient acceptance, or patient assessment of abdominal pain.

Adult↗
PubMed1998

Measuring the ability to meet family needs in an intensive care unit.

OBJECTIVE: To measure the ability to meet family needs in an intensive care unit (ICU). DESIGN: Descriptive survey. SETTING: University hospital ICU. SUBJECTS: Ninety-nine next of kin respondents and 16 secondary family respondents were recruited. INTERVENTIONS: A modified Society of Critical Care Medicine Family Needs Assessment instrument was used. MEASUREMENTS AND MAIN RESULTS: Demographic variables included patient age, gender, diagnosis, Acute Physiology and Chronic Health Evaluation (APACHE) II score on admission, Therapeutic Intervention Scoring System (TISS) score on the date of interview, cumulative TISS of the ICU on the day of interview, number of patients in the ICU at time of interview, nurse/patient ratio for the patient, average nurse/patient ratio of the entire unit, day of the week of the interview, timing of the interview, number of ICU attending physicians who cared for this patient (scheduled for a period of seven consecutive days), number of nurses who cared for the patient, if a nurse was assigned the same patient on two consecutive days worked, length of stay in the ICU, and length of hospital stay. Demographic information concerning the family member included gender, age, commuting time to the hospital, visiting time in the hospital per day, number in family group, relationship to the patient, ethnic background, and education level. The additive score of all questions in the needs assessment instrument was calculated and used as the dependent variable. The independent variables were demographic information concerning patients, ICU, and respondents. The model coefficient of determination (R2adj) was 0.20 with a p = .0079. Greater family dissatisfaction (i.e., higher score) was present if there were more than two ICU attendings per patient (p = .048), or if the same nurse was not assigned on two consecutive days (p = .044). Family satisfaction increased if the respondent was female (p = .006), if the patient had a higher APACHE II score (p = .007), and if the patient's relationship with the most significant family member was brother/sister (p = .012). The family needs instrument was reliable and demonstrated a high degree of concordance with a second respondent in the same family surveyed. CONCLUSIONS: Communication by the same provider was important when measuring the ability of an ICU to meet family needs. Instrument scores and the ability to meet family needs differed depending on the gender and the relationship to the patient of the most significant family member. We speculate that this instrument may be a useful adjunct in assessing quality of critical care services provided.

APACHE↗
PubMed1996

Influences on adolescent eating behavior.

PURPOSE: The food consumption behavior of American adolescents often fails to meet dietary recommendations, indicating the need for investigation of the factors that influence this behavior. This study, guided by Bandura's Social Cognitive Theory, examined relationships between such behavior and other personal, environmental, and behavioral variables. METHODS: A paper-and-pencil instrument was administered to a sample of 242 high school students. "Pyramid," fat, and sugar food scores were calculated to measure subjects' dietary diversity along with their consumption of fats and sugar/sweets. Statistical analyses were conducted to identify relationships between subjects' food scores and other study variables. RESULTS: Male and female subjects' pyramid scores were positively related (p < or = 0.05) to the number of meals they consumed daily. Some gender differences emerged in the data, as conformity to parents, snack consumption, and consumption of meals and snacks from home predicted males' Pyramid scores, while amount of physical exercise predicted pyramid scores of females. Both male and female subjects' fat and sugar scores were positively related (p < or = 0.05) to their consumption of meals and snacks from the school cafeteria and overall snack consumption and negatively related to their self-efficacy for making healthful food choices. Females' fat scores were further predicted by their consumption of fast food. CONCLUSIONS: Different aspects of adolescents' food consumption behavior may be influenced by different factors, which may vary between males and females. Therefore, nutrition and health professionals should tailor educational and treatment strategies according to both the gender of their patients and the specific desired dietary outcomes.

Adolescent↗
PubMed1995

Leadership development: educating nurse practitioners for the future.

The development of leadership potential is recognized to be an essential component of nurse practitioner education to prepare graduates for a dynamic health care system. Leadership potential refers to those skills that enable a nurse practitioner to function as a change agent and to effectively resolve conflict. The purpose of the study was to examine personal variables (personality type, self-esteem, and learning style) with respect to the leadership potential of pediatric nurse practitioner graduates over a 3-year period. The research study was descriptive, and data were analyzed using descriptive statistics. The subjects consisted of 21 female students who completed five instruments used to measure the relationships between variables and leadership potential. Significant results were found between those students who learned abstractly and the ability to function effectively as a change agent post-program.

Adult↗
PubMed1996

Predicting disability in stroke--a critical review of the literature.

Research articles on the prognosis of stroke patients were analysed to identify studies that met sound methodological principles of prognostic research as well as to identify variables capable of predicting functional outcome (ADL) after stroke. Data sources comprised a computer-aided search of published prognostic studies and references to literature used in prognostic studies. Seventy-eight studies were tested for adherence to the following key methodological criteria: reliability and validity of measurement instruments used to assess dependent and independent variables; inclusion of an inception cohort; adequate and uniform end-point of observation; control for drop-outs during period of observation; statistical testing of presumed relationship between dependent and independent variables; sufficient sample size in relation to number of determinants; control for multicollinearity; specification of patient characteristics (i.e. age, type, recurrent stroke and localization of stroke); description of interfering treatment effects during the period of observation, and cross-validation of the prediction model in a second independent group of patients. Only three studies satisfied nine out 11 criteria and ten studies eight criteria for the determination of valid prognostic research. The results of these studies indicate that the following variables are valid predictors for functional recovery after stroke: age; previous stroke; urinary continence; consciousness at onset; disorientation in time and place; severity of paralysis; sitting balance; admission ADL score; level of social support and metabolic rate of glucose outside the infarct area in hypertensive patients. This study supports the general opinion that not only are differences in objectives and heterogeneity in stroke patients responsible for the lack of accuracy in predicting functional outcome, but also the methodological flaws in published prognostic research.

Activities of Daily Living↗
PubMed2005

Biological and social predictors of long-term geriatric depression outcome.

OBJECTIVE: In this study, we examined 204 older depressed individuals for up to 64 months to determine factors related to depression outcome. We hypothesized that both presence of vascular brain lesions seen on baseline magnetic resonance imaging (MRI) scans and lower baseline social support measures would be related to worse depression outcome. METHOD: At study entry, all subjects were at least 59 years old, had a diagnosis of major depression, and were free of other major psychiatric illness and primary neurological illness, including dementia and stroke. Depression was diagnosed via structured interview and clinical assessment by a geriatric psychiatrist who completed a Montgomery Asberg Depression Rating Scale (MADRS) to determine severity of depression. Subjects provided self-report data on social support variables and ability to perform basic and instrumental activities of daily living (ADL, IADL). All subjects agreed to have a baseline standardized MRI brain scan. Ratings of severity of hyperintensities were determined for the periventricular white matter, deep white matter, and subcortical gray matter by two readers who decided by consensus. Treatment was provided by geropsychiatrists following clinical guidelines. Using mixed models to analyze the data, we determined the effect of a variety of demographic, social and imaging variables on the trajectory of MADRS score, the outcome variable of interest. RESULTS: MADRS scores decreased steadily over time. In a final HLM model, in which time since entry, a baseline time indicator, age, gender, education and Mini-mental State Examination score were controlled, subjective social support, instrumental ADL impairment, subcortical gray matter severity, and the interactions of time with social network and with subcortical gray matter lesions remained significantly associated with MADRS score. CONCLUSIONS: Both social and biological factors at baseline are associated with longitudinal depression severity in geriatric depression.

Aged↗
PubMed2002

Biomechanics feedback for rowing.

Factors that affect boat speed are important determinants of rowing performance and should form the basis of feedback to rowers and their coaches. Biomechanical analysis of rowing has led to variables that are causally linked to boat speed. With modern technology, these variables can be measured and feedback can be presented instantaneously on-water, or be presented simultaneously with video after the event. This paper demonstrates the links between the criterion of success in rowing, the time for completing 2000 m and the forces acting on the boat, and describes an instrumentation system for providing feedback of these variables to rowers and coaches. These feedback techniques have been used with rowers from national to Olympic competition standard. Aspects of technique have been linked to the determinants of boat speed and several examples are presented here. The motor learning literature supports the effectiveness of kinetic information feedback for the improvement of motor skill and provides a relevant conceptual framework for the improvement of rowing performance. However, although rowers and their coaches value this feedback, further research must be undertaken to establish a sound basis for comparing the effectiveness of such feedback compared with traditional styles, such as verbal feedback of performance.

Biofeedback, Psychology↗
PubMed2005

Impact of osteoarthritis on the rehabilitation of patients following a stroke.

OBJECTIVE: To determine if functional gain for patients following stroke rehabilitation is adversely affected by osteoarthritis (OA). METHODS: A retrospective cohort analysis was conducted using data collected between 1994 and 2001 from a large national registry of US rehabilitation inpatients. Outcome variables were functional status (the Functional Independence Measure [FIM Instrument]) at discharge and followup, FIM gain during and after rehabilitation, length of stay, and discharge setting. The primary predictor variable was the presence of OA. Covariates were age, sex, race, other comorbidities, type of stroke, length of stay, and time to followup. Analysis was by multivariable regression. RESULTS: Data from 3,094 patients with OA and 44,943 patients without OA admitted following a stroke to inpatient rehabilitation facilities were analyzed. In unadjusted analyses, OA was associated with significantly higher FIM ratings than patients without OA at admission (mean +/- SD 65.7 +/- 19.2 versus 63.1 +/- 20.5; P < 0.001) and discharge (mean +/- SD 89.2 +/- 21.8 versus 87.7 +/- 23.0; P < 0.001), but with lower FIM ratings at followup (mean +/- SD 97.7 +/- 24.7 versus 99.7 +/- 24.9; P < 0.001). In multivariate analyses, adjusting for potential confounders, OA was associated with a 1.62-day increase in length of stay (95% confidence interval [95% CI] 1.15, 2.08) and a 1.37 smaller improvement in FIM scores between admission and followup (95% CI 0.62, 2.12). This smaller increase in FIM instrument score was caused by less improvement in FIM after discharge. CONCLUSION: OA impairs recovery from stroke. This is compensated for by longer length of stay for inpatient medical rehabilitation. Reimbursement systems may need to consider the impact of OA as a comorbid condition in patients receiving stroke rehabilitation.

Aged↗
PubMed1988

Developing an original tool for research.

An instrument must be tested for validity and reliability before it can be used to measure the variables of interest specified in the research design. If the instrument is not valid and reliable, then the results of a study have limited credibility or usefulness in practice. The process is meticulous, but the results are gratifying when new data on nurse practitioners can be generated.

Attitude of Health Personnel↗
PubMed2006

Improving measurement in health education and health behavior research using item response modeling: comparison with the classical test theory approach.

This paper compares the approach and resultant outcomes of item response models (IRMs) and classical test theory (CTT). First, it reviews basic ideas of CTT, and compares them to the ideas about using IRMs introduced in an earlier paper. It then applies a comparison scheme based on the AERA/APA/NCME 'Standards for Educational and Psychological Tests' to compare the two approaches under three general headings: (i) choosing a model; (ii) evidence for reliability--incorporating reliability coefficients and measurement error--and (iii) evidence for validity--including evidence based on instrument content, response processes, internal structure, other variables and consequences. An example analysis of a self-efficacy (SE) scale for exercise is used to illustrate these comparisons. The investigation found that there were (i) aspects of the techniques and outcomes that were similar between the two approaches, (ii) aspects where the item response modeling approach contributes to instrument construction and evaluation beyond the classical approach and (iii) aspects of the analysis where the measurement models had little to do with the analysis or outcomes. There were no aspects where the classical approach contributed to instrument construction or evaluation beyond what could be done with the IRM approach. Finally, properties of the SE scale are summarized and recommendations made.

Data Interpretation, Statistical↗
PubMed2006

Engineering challenges of BioNEMS: the integration of microfluidics, micro- and nanodevices, models and external control for systems biology.

Systems biology, i.e. quantitative, postgenomic, postproteomic, dynamic, multiscale physiology, addresses in an integrative, quantitative manner the shockwave of genetic and proteomic information using computer models that may eventually have 10(6) dynamic variables with non-linear interactions. Historically, single biological measurements are made over minutes, suggesting the challenge of specifying 10(6) model parameters. Except for fluorescence and micro-electrode recordings, most cellular measurements have inadequate bandwidth to discern the time course of critical intracellular biochemical events. Micro-array expression profiles of thousands of genes cannot determine quantitative dynamic cellular signalling and metabolic variables. Major gaps must be bridged between the computational vision and experimental reality. The analysis of cellular signalling dynamics and control requires, first, micro- and nano-instruments that measure simultaneously multiple extracellular and intracellular variables with sufficient bandwidth; secondly, the ability to open existing internal control and signalling loops; thirdly, external BioMEMS micro-actuators that provide high bandwidth feedback and externally addressable intracellular nano-actuators; and, fourthly, real-time, closed-loop, single-cell control algorithms. The unravelling of the nested and coupled nature of cellular control loops requires simultaneous recording of multiple single-cell signatures. Externally controlled nano-actuators, needed to effect changes in the biochemical, mechanical and electrical environment both outside and inside the cell, will provide a major impetus for nanoscience.

Animals↗
PubMed2004

Effect of wheelchair stroke pattern on mechanical efficiency.

OBJECTIVE: To investigate the effect of different wheelchair stroke patterns on efficiency and propulsion technique (force application and timing). DESIGN: Inexperienced, able-bodied subjects were randomly divided into two velocity groups (1.11 m/sec [n = 13] and 1.39 m/sec [n = 11]). An external (medium) load was set at 0.23 N/kg. Subjects performed four 4-min exercise blocks on a wheelchair ergometer. The first block was performed with a freely chosen movement pattern of the hand. Thereafter, the pumping, semicircular, or single-looping over propulsion pattern were performed in a counterbalanced order. Gross mechanical efficiency and propulsion technique variables were measured with Oxycon Alpha and an instrumented wheelchair ergometer. RESULTS: A significant difference was found for mechanical efficiency, with pumping showing the highest efficiency and semicircular the lowest efficiency, regardless of velocity. Timing variables and negative power deflections before and after the push phase showed significant differences between the stroke patterns. CONCLUSIONS: Pumping is the energetically most efficient stroke pattern in contrast to the semicircular pattern in this subject group. Propulsion technique could not explain the difference in efficiency.

Adult↗
PubMed1984

Fetal weight estimation from lengths and volumes found by three-dimensional ultrasonic measurements.

A custom-built computer system combined with a commercial real-time ultrasonic scanner was used to predict fetal weight. A special three-dimensional (3D) locating system provided 3D coordinates of fetal surface points imaged on multiple ultrasound scans. The 3D coordinates were used to develop length and volume variables that are not available with commercial instruments. Multiple regressions were used to compare these lengths and volumes with more conventional diameters and circumferences for their ability to predict fetal weight. Measurements were made on 41 live fetuses within 48 hours prior to delivery (weight range 1,985-4,734 g, mean weight 3,421 g). Combinations of 19 measured variables were analyzed against birth weight and the natural log of birth weight. The correlation between log birth weight and combinations including lengths from 3D measurements was R = .93, SE = 73 g/kg. When volumes from 3D measurements (which are much more difficult to obtain) were added, the correlation was R = .94, SE = 69 g/kg. These results suggest that lengths from 3D measurements have the potential to improve fetal weight prediction by 25-30 per cent over current methods, which have an approximate error of 100 g/kg. The relative lack of improvement with volumes from 3D measurements is probably the result of technical problems which may be overcome with further research.

Birth Weight↗
PubMed2005

Methodological issues in determining the dimensionality of composite health measures using principal component analysis: case illustration and suggestions for practice.

During the early steps of the construction of composite health measures, principal component analysis (PCA) is commonly used to identify 'latent' factors that underlie observed variables and to determine the dimensionality of the instruments. The determination of the number of components to retain is critical to PCA: it markedly influences the factorial model identified and further conditions the validity of the constructed instrument. However, many researchers developing composite health measures seem to be unaware of the importance of this determination. The purposes of the paper are to illustrate (1) the variability of the factorial models obtained by using different published rules (n = 10) for determining the number of components to retain in PCA applied to two quality-of-life datasets, and (2) the value of a careful and diversified approach to the problem of the number of components to retain in PCA that we suggest, instead of the unsatisfactory 'rule-of-thumb' that many researchers use. This involves: (1) using robust rules (including parallel analysis and minimum average partial procedure) to generate a set of possible values for the number of components to retain, (2) repeating the analysis across samples, (3) comprehensively assessing the models obtained, and (4) considering complementary methods to PCA and especially confirmatory factor analysis.

Factor Analysis, Statistical↗
PubMed2001

[Prevalence and factors associated with burnout in a health area].

OBJECTIVES: The main objective was to determine the prevalence of the burnout syndrome among health workers and its distribution by social, demographic and work variables. The secondary aim was to detect potentially modifiable causes. DESIGN: Descriptive cross-sectional study. SETTING: Primary care. PARTICIPANTS: All the 354 doctors, nurses and clinical auxiliaries belonging to the 22 primary care teams of Area VI, Madrid. MEASUREMENTS AND MAIN RESULTS: A self-administered, anonymous questionnaire was sent out by internal mail. This had three instruments: a questionnaire on social and demographic variables, the validated questionnaire known as the Maslach Burnout Inventory and an open opinion section. High levels of burnout were detected: 30.6% in the high range on the emotional tiredness sub-scale, with higher scores among men (p = 0.026). There were also more paediatric staff affected in personal achievements. There was scant relationship of the syndrome to social variables. 43.9% thought they suffered or had suffered from some kind of physical or psychological disorder directly related to exercising their profession. 38.3% associated directly their burnout with the excess demand habitually experienced in clinics. CONCLUSIONS: We detected worryingly high levels of this syndrome among our professionals, similar to other surveys in Spain. The subjects of the survey linked their unease with certain work factors that could easily be modified. The training received in techniques of self-control and stress management is clearly insufficient.

Burnout, Professional↗