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PubMed2003

A reassessment of normal cervical range of motion.

STUDY DESIGN: Intraexaminer and interexaminer/procedure reliability and error analysis using a repeated-measures design. OBJECTIVE: To quantify sources of discrepancies in cervical range of motion values between two procedures that use the same potentiometric technology. SUMMARY OF BACKGROUND DATA: Studies using an early version of an electrogoniometer system, which was connected between a helmet worn by the study participant and a chair on which they sat, reported unusually high values for active and passive cervical range of motion, although measurements were reliable. To understand the sources of the discrepancies between that study and later studies (using upgraded software), the current study was designed to quantify possible sources of error contributed by various components of the procedures: helmet, thoracic reference, chair, and software. METHODS: A total of 22 asymptomatic study participants were evaluated in two separate sessions, 1-3 days apart. Components of two procedures were changed systematically in a series of repeated measurements to provide concurrent reliability and to assess sources of error between the two procedures. RESULTS: The reliabilities of both procedures were generally high with no systematic trends, except for lower values for flexion-extension studies with Procedure 2. Procedure 2 also provided systematically greater range of motion values (2-8 degrees ) than Procedure 1, except for flexion (half-cycle). The source of the greatest discrepancy between the two procedures was the software, when comparing the original with the updated versions. With regard to the instrumentation, the greatest source of variability was in the thoracic reference post; next was the helmet, and least significant was the type of seat used. A comparison of overall procedure discrepancies and summation of individual elements of the procedures accounted for virtually all of the observed error. CONCLUSION: The potentiometer-based electrogoniometer is a reliable instrument for determining cervical range of motion. Measurements appear to be more valid when the thoracic reference point is physically attached to the study participant's body. The original software provided with the system appears to have contributed to systematic overestimation of ranges of motion, but current units provide measurements that are both reliable and valid.

Adult↗
PubMed2002

Subjective quality of life, health, I-ADL ability and adaptation strategies in fibromyalgia.

OBJECTIVES: To describe subjective quality of life and health, self-perceived instrumental activities of daily living (I-ADL) ability and adaptation strategies, and to explore possible relationships between these variables in fibromyalgia patients. DESIGN: Two instruments were used with fibromyalgia patients: the Fibrositis Impact Questionnaire and 'Living with fibromyalgia - adaptation to chronic disease and handicap', and correlative analyses were performed. SUBJECTS: A sample of 34 patients undergoing rehabilitation (in a specific programme). RESULTS: The majority of the patients used many adaptation strategies, demonstrating some significant relationships with perceived I-ADL ability and subjective quality of life and health. Different symptoms correlated highly significantly with self-perceived ability in I-ADL. CONCLUSION: The significant relationships between adaptation strategies and I-ADL ability and health demonstrated deserve clinical awareness and further research efforts.

Activities of Daily Living↗
PubMed1996

Sympathovagal interplay in the control of overall blood pressure variability in unanesthetized rats.

The role of sympathetic and parasympathetic influences in the control of overall blood pressure variability was studied in chronically instrumented, freely behaving Wistar-Kyoto rats (WKY) and spontaneously hypertensive rats (SHR) subjected to sympathectomy by 6-hydroxydopamine (100 micrograms/kg ip) twice in 1 wk (effectiveness verified by abolition of pressor and tachycardic response to tyramine, 150 mg/kg i.v.) and/or to cholinergic blockade by atropine (0.7 mg/kg i.v.). Overall heart rate and blood pressure variabilities were measured as variation coefficients computed beat to beat on 90-min blood pressure recordings. As compared with the vehicle-treated controls, sympathectomized rats had much larger blood pressure variability (WKY, +61%, SHR, +86%, both P < 0.01). Cholinergic blockade superimposed to sympathectomy caused heart rate variability to markedly fall and the already augmented blood pressure variability to further rise 47% in WKY and 28% in SHR (both P < 0.01). Prolonged observation of the animals revealed the systematic occurrence of rapid blood pressure falls occurring at the onset of locomotor activity, accounting for a substantial fraction of the sympathectomy-related increase in blood pressure variability. It is concluded that 1) under undisturbed daily life conditions, sympathetic influences oppose blood pressure variations, presumably by adjusting their vasoconstrictor influences to compensate for the metabolic vasodilation occurring in functionally active tissues; 2) when sympathetic vascular control is lost, vagally mediated heart rate variations oppose the rise in blood pressure variability, possibly via rapid changes in cardiac output that partly offset the fluctuations in total peripheral resistance; and 3) chronic hypertension fails to alter these cardiovascular regulatory mechanisms.

Animals↗
PubMed2003

Changes in the components of moral reasoning during students' medical education: a pilot study.

INTRODUCTION: Many authors are concerned by students' moral reasoning not developing normally during medical education. AIM: This study is concerned with how the components of student' moral reasoning are affected by their medical studies. METHODS: Ninety-two medical students were tested on entry into first year and on finishing third year, to determine evolutionary changes in their moral reasoning. Changes in their use of arguments specific to each stage of moral development were measured. RESULTS: Significant changes were observed in the weighted global score (-18.14 +/- 59.17, P = 2.8%). Changes in global score correlated with changes in stages of moral reasoning. The multivariate structure of moral reasoning was reorganised into two principal components, which, respectively, explained almost 82% (first year) and 72% (third year) of the total variability in scores. Moral reasoning stages characterized by law-and-order and social-contract/legalistic orientations proved important for explaining the variability in students' moral reasoning at the start of medical training, while instrumental-relativist and interpersonal-concordance orientations explained variability post third year. CONCLUSIONS: Students restructure their handling of ethical questions by using arguments with more instrumental-relativist and interpersonal-concordance orientations, rather than those of the more desirable law-and-order or social-contract/legalistic type. To assess better the skills required for moral reasoning, a more sophisticated approach is needed than that of a simple measure of improvement/stagnation/deterioration.

Adult↗
PubMed2004

Variations in health status within and between socioeconomic strata.

OBJECTIVES: To analyse the variability in health status within as well as between socioeconomic groups. What is the range of individual variability in the health effects of socioeconomic status? Is the adverse effect of lower socioeconomic status uniform across the entire distribution of health status? DESIGN: Nationally representative telephone survey of the US population in 1996. SETTING: 60 US metropolitan and rural areas. PARTICIPANTS: 47 076 adult respondents to the community tracking study. MAIN OUTCOME MEASURES: Self rated physical and mental health status, measured by the Short Form-12 instrument. RESULTS: There is considerable variability in self rated health within socioeconomic strata and that variability increases in a step-wise fashion at each lower stratum of income. Most of the increased variability is accounted for by changes in the middle and lower (10th, 25th, and 50th centiles) rather than the upper (75th and 90th) portions of the distribution. A resilient subgroup of lower socioeconomic status people seems to maintain excellent self rated health throughout life, while a more vulnerable lower socioeconomic status group experiences rapid deterioration in health status as people reach middle age. CONCLUSIONS: Within the population level social structuring of health there are differences in individual resilience and vulnerability that are amenable to further exploration and potential modification.

Adolescent↗
PubMed1999

Activities and functional assessment 1 year after spinal fusion for paralytic scoliosis.

The results of spinal fusion in patients with paralytic deformities are usually presented as the correction of the deformity. When evaluating the surgical results in such patients, it is advantageous to classify the patients into subgroups because of the varying dysfunction and disabilities. The aim of this study was to evaluate the effect of spinal fusion in patients with paralytic scoliosis in relation to function in terms of Impairments, activities in terms of Disabilities, and dependence in terms of Handicaps 1 year postoperatively, with emphasis on subgroups. A total of 94 patients with paralytic scoliosis and 18 different diagnoses were evaluated 1 year after surgery. The patients were classified according to whether or not they could understand verbal instructions. The patients were also grouped according to the Scoliosis Research Society classification of diagnoses. A set of instruments was used with the variables classified according to WHO's International Classification of Impairments, Disabilities, and Handicaps (ICIDH). This consists of the patient's/relative's motives for surgery, persistent skin discoloration, ambulating or use of wheelchair, use of a brace, sitting balance, weight distribution on a sitting surface, angle of scoliosis, reaching, pain estimation, activities of daily living (ADL) Klein and Bell, care given, time spent resting, and seating supports. The set of instrument also included a follow-up questionnaire comprising 12 different areas, where the patients/relatives assessed the results of surgery. The study showed that spinal fusion in paralytic scoliosis led to showed improvements in the whole group of patients at the Impairment level in the angle of scoliosis, sitting balance, weight distribution, and reduced number of patients with persistent skin discoloration, and at the Handicap level in reduced time for resting during the day, reduced number of seating supports in the wheelchair, and in the use of a brace. Most of the parameters were unchanged. The results in the subgroups were almost the same as in the whole group, although pain and reaching at the Impairment level, and ADL at the Disability level, could not be measured in the patients who were unable to understand verbal instructions. The subjectively assessed results showed that seating posture was ranked positively irrespective of the motive for surgery. The study showed that the patients with paralytic scoliosis maintained or improved their function and level of independence in terms of Impairment and Handicap 1 year postoperatively. The subjective results assessed by the patients/relatives also showed a positive outcome of surgery. Weight distribution on a seating surface was improved, but still uneven, and with respect to better sitting balance and increasing time sitting in a wheelchair, this can involve a risk for pressure sores and needs further investigation. When introducing outcomes including the Disability level, one must take the importance of homogeneity in the groups into consideration.

Activities of Daily Living↗
PubMed2000

[Errors in keratometry for intraocular lens implantation in infants].

UNLABELLED: To evaluate investigator- and instrument-dependent errors of keratometry in children and their possible influence on the predicted postoperative refraction after intraocular lens implantation. METHODS: Keratometry readings of five children with congenital cataract were taken preoperatively under general anesthesia (age 1.5-7.5 months, mean = 4.4 months). Both eyes were measured by two investigators with a manual Zeiss keratometer and an Alcon portable automated keratometer. Three measurements were performed with each instrument. Axial length was determined with ultrasound and the SRK II-formula was used for intraocular lens calculation. RESULTS: The investigator-dependent variability was 0.22 mm +/- 0.07 SEM for the manual keratometer and 0.20 mm +/- 0.07 SEM for the automated keratometer. The instrument-dependent variability was 0.44 mm +/- 0.12 SEM for investigator A and 0.34 mm +/- 0.09 SEM for investigator B. These results suggest that deviation from the required postoperative refraction of up to 6.0 D has to be expected in individual cases if intraocular lenses are implanted. CONCLUSIONS: The lack of fixation in children who have keratometry under general anesthesia leads to inaccurate keratometry readings, which will cause rather high deviations of the precalculated postoperative refraction. Our results explain the high rate of residual refractive errors reported in the literature after intraocular lens implantation in children. In order to improve the accuracy of keratometry multiple measurements of corneal curvature should be taken.

Age Factors↗
PubMed1998

Identification of variables needed to risk adjust outcomes of coronary interventions: evidence-based guidelines for efficient data collection.

OBJECTIVES: Our objectives were to identify and define a minimum set of variables for interventional cardiology that carried the most statistical weight for predicting adverse outcomes. Though "gaming" cannot be completely avoided, variables were to be as objective as possible and reproducible and had to be predictive of outcome in current databases. BACKGROUND: Outcomes of percutaneous coronary interventions depend on patient risk characteristics and disease severity and acuity. Comparing results of interventions has been difficult because definitions of similar variables differ in databases, and variables are not uniformly tracked. Identifying the best predictor variables and standardizing their definitions are a first step in developing a universal stratification instrument. METHODS: A list of empirically derived variables was first tested in eight cardiac databases (158,273 cases). Three end points (in-hospital death, in-hospital coronary artery bypass graft surgery, Q wave myocardial infarction) were chosen for analysis. Univariate and multivariate regression models were used to quantify the predictive value of the variable in each database. The variables were then defined by consensus by a panel of experts. RESULTS: In all databases patient demographics were similar, but disease severity varied greatly. The most powerful predictors of adverse outcome were measures of hemodynamic instability, disease severity, demographics and comorbid conditions in both univariate and multivariate analyses. CONCLUSIONS: Our analysis identified 29 variables that have the strongest statistical association with adverse outcomes after coronary interventions. These variables were also objectively defined. Incorporation of these variables into every cardiac dataset will provide uniform standards for data collected. Comparisons of outcomes among physicians, institutions and databases will therefore be more meaningful.

Adult↗
PubMed2004

Responsiveness of health-related quality of life outcome measures in cardiac rehabilitation: comparison of cardiac rehabilitation outcome measures.

Assessment instruments that are not responsive to change are unsuitable as outcome tools in cardiac rehabilitation because they underestimate the psychosocial benefits of program attendance. Nine questionnaires were assessed for responsiveness with the standardized response mean (SRM). Questionnaires were allocated into 3 batteries, and each battery was completed by cardiac rehabilitation and comparison participants at 2 time points (411 and 375 participants in total, respectively). There was a high degree of variability in the responsiveness of instrument subscales. The positive affect subscale of the Global Mood Scale (J. Denollet, 1993a) was the most responsive (SRM = 0.62). Further information on the comparative responsiveness of psychosocial scales is important to optimize instrument selection for outcome studies.

Female↗
PubMed1997

[Measurement of reliability and validity of clinical instruments].

In biomedical measurement, comparisons between two instruments or between a new instrument and the gold standard is commonly needed to evaluate the reliability and validity of the instruments. Such studies are frequently analyzed using statistics that are inappropriate for studying concordance. This article reviews the appropriate statistical techniques and provides a current methodological guide for the evaluation of reliability and validity of instruments used in the measurement of biomedical variables. The techniques are illustrated using real data from a pilot study comparing four instruments for measuring cholesterol.

Blood Chemical Analysis↗
PubMed2006

Exercise motivation, eating, and body image variables as predictors of weight control.

PURPOSE: This study investigated changes in psychosocial variables related to exercise, eating, and body image during a weight reduction program and evaluated their association with weight loss in middle-aged overweight and obese women up to 1 yr after intervention. METHODS: The 136 participants (age, 48.1 +/- 4.4 yr; weight, 30.6 +/- 5.6 kg x m(-2)) who completed the 4-month lifestyle weight reduction program (86% retention), losing -6.2 +/- 4.6% (P < 0.001) of their initial weight, were followed up for 12 additional months. Of these, 82% completed 16-month assessments (weight change, -5.5 +/- 7.7%, P < 0.001). Psychosocial variables were assessed by validated instruments in standardized conditions at baseline and after the intervention (4 months). RESULTS: Compared with 4-month assessments, body weight did not change at 16 months (P > 0.09). Changes in eating restraint, disinhibition, and hunger; exercise, self-efficacy, and intrinsic motivation; body shape concerns; and physical self-worth were associated with weight change at 4 months (P < 0.001, except hunger, P < 0.05). Baseline-adjusted 4-month scores in all psychosocial variables also predicted weight change from baseline to 16 months (P < 0.01), except hunger (P > 0.05). After controlling for 4-month weight change and other covariates, increases in exercise intrinsic motivation remained predictive of weight loss at 16 months (P < 0.05). Multiple linear regression showed that eating variables were significant and independent correlates of short-term weight change, whereas changes in exercise variables were stronger predictors of longer term weight outcomes. CONCLUSIONS: Results highlight the importance of cognitive processes during weight control and support the notion that initial focus on diet is associated with short-term weight loss, while change in exercise-related motivational factors, with a special emphasis on intrinsic sources of motivation (e.g., interest and enjoyment in exercise), play a more important role in longer term weight management.

Adult↗
PubMed1980

Mechanisms of beat-to-beat variability in the heart rate of the neonatal lamb. II. Effects of hypoxia.

The effects of acute hypoxia on the resting arterial pressure as well as on heart rate and its beat-to-beat variability were studied in chronically instrumented, unanesthetized newborn lambs at 2 to 8 weeks of neonatal life. Lung ventilation with a gas mixture containing 10% oxygen and 3% carbon dioxide decreased arterial blood PO2 by about 50% in all animals regardless of age without significantly altering blood pH and PCO2. This degree of hypoxia produced a mild pressor response, accompanied by a significant tachycardia; the pattern of these changes, however, differed somewhat according to neonatal growth. The impact of hypoxia on beat-to-beat variability of the neonatal heart rate also varied with age. When the lambs were 2 to 3 weeks old, both the long- and short-term variabilities decreased progressively during hypoxia and the decrement reached a maximum at 10 minutes of oxygen deprivation. As the lambs became older, however, there was some initial and transient increase in the long- and short-term variabilities in the early period of hypoxia but thereafter the changes were inconsistent. The significance of these observations is discussed in terms of our knowledge of the pathophysiologic alterations in the cardiovascular system produced by acute hypoxia.

Aging↗
PubMed2004

Salient variables for treatment research of adolescent alcohol and other substance use disorders.

AIMS: To seek a level of uniformity and consistency in the type of data or variables collected to allow cross-study comparison and ease in meta-analyses of adolescent treatment studies. DESIGN: The rationale for adoption of such a core set of variables for adolescent treatment research, the main categories and specific types of variables, methods for collecting these variables, including the use of specific instruments are reviewed and discussed. FINDINGS: There is a relatively small number of adolescent treatment outcome studies. Between studies, there are highly variable methodologies, including differences in how outcome or treatment success is measured, differences in ascertainment in substance use, differences in the measurement of non-substance use variables such as social and academic functioning, poor follow-up rates and a lack of comparison groups in many studies. CONCLUSIONS: Differences in the types and collection of baseline and outcome variables and the need to achieve some level of uniformity across adolescent substance use disorders (SUD) treatment studies suggest that investigators interested in adolescent treatment outcome research should develop a set of 'core variables' that are relatively consistent, or at least comparable, across studies.

Adolescent↗
PubMed1987

Inverse relationship between heart rate and blood pressure variabilities in rats.

The interplay of heart rate variability, baroreceptor control of heart rate, and blood pressure (BP) variability was examined in chronically instrumented, unanesthetized, freely moving rats in which the efferent neural influences on heart rate were pharmacologically altered. In each rat, BP was recorded continuously for 90 minutes in the control condition and in one or more of the following conditions: 1) beta-adrenergic receptor blockade by propranolol, 1 mg/kg; 2) cholinergic blockade by atropine, 0.75 mg/kg, and 3) combined blockade by propranolol plus atropine. Each BP recording was analyzed beat-to-beat by a computer that calculated heart rate and BP variabilities, both expressed as variation coefficients. In addition, under each condition the sensitivity of the arterial baroreceptor control of heart rate was assessed by measuring the reflex changes in pulse interval in response to BP changes induced by bolus i.v. injections of phenylephrine and nitroprusside. As compared with the control condition, 1) propranolol (n = 10) reduced heart rate variability by 23 +/- 4% (p less than 0.01), only slightly impaired baroreceptor reflex sensitivity, and did not significantly modify BP variability (+11 +/- 7%); 2) atropine (n = 11) reduced heart rate variability by 30 +/- 7% (p less than 0.01), drastically impaired baroreceptor reflex sensitivity, and increased BP variability (+40 +/- 8%, p less than 0.01); 3) combined blockade (n = 10) caused variability and baroreceptor reflex changes similar to those induced by atropine alone. Thus, heart rate variability depends on both vagal and sympathetic influences. However, only the former component affects BP variability, that is, it plays an antioscillatory role.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed2001

The effect of aircraft control forces on pilot performance during instrument landings in a flight simulator.

BACKGROUND: Pilots may have difficulty controlling aircraft at both high and low force levels due to larger variability in force production at these force levels. The aim of this study was to measure the force variability and landing performance of pilots during an instrument landing in a flight simulator. METHODS: There were 12 pilots who were tested while performing 5 instrument landings in a flight simulator, each of which required different control force inputs. Pilots can produce the least force when pushing the control column to the right, therefore the force levels for the landings were set relative to each pilot's maximum aileron-right force. The force levels for the landings were 90%, 60%, and 30% of maximal aileron-right force, normal force, and 25% of normal force. Variables recorded included electromyographic activity (EMG), aircraft control forces, aircraft attitude, perceived exertion and deviation from glide slope and heading. Multivariate analysis of variance was used to test for differences between landings. RESULTS: Pilots were least accurate in landing performance during the landing at 90% of maximal force (p < 0.05). There was also a trend toward decreased landing performance during the landing at 25% of normal force. Pilots were more variable in force production during the landings at 60% and 90% of maximal force (p < 0.05). CONCLUSION: Pilots are less accurate at performing instrument landings when control forces are high due to the increased variability of force production. The increase in variability at high force levels is most likely associated with motor unit recruitment, rather than rate coding. Aircraft designers need to consider the reduction in pilot performance at high force levels, as well as pilot strength limits when specifying new standards.

Adult↗
PubMedDate not supplied

The Nurse Practitioner Rating Form. Part I: Conceptual development and potential uses.

Most research and evaluation studies of nurse practitioner practice have used data collection instruments developed for that specific study, choosing and defining variables of interest to them and developing ad hoc measurement instruments with psychometric properties that are largely unknown. The primary focus of such studies and the instruments used in them has been on activities related to the assessment and management of medical problems. Such focus in the early studies is understandable, since these are the activities that have been added to the traditional nursing functions to form the nurse practitioner role. However, the nursing components of the role, such as patient teaching and attention to patients' psychosocial needs, have not been adequately studied. The Nurse Practitioner Rating Form (NPRF) was designed specifically to measure both the medical and nursing components of the nurse practitioner role.

Communication↗
PubMed2004

Test-retest stability of neuropsychological testing and individual differences in variability in schizophrenia outpatients.

The accurate measurement of neurocognitive function requires stable and reliable instruments. These assessments are critically important as correlates, predictors, and outcome measures of psychopathology, neuropathology, and treatment. Particularly, in studies that evaluate the impact of treatments on neurocognitive function, it is essential that their reliability as repeated measures be quantified. In an attempt to measure within- and between-subject variance on a battery of neuropsychological tests commonly used in schizophrenia research, baseline measures were administered twice, approximately 10 weeks apart, to 54 stable outpatients with schizophrenia or schizoaffective disorder. Instruments were judged for their stability, and individuals were assessed for individual differences in test-retest variability. The majority of the instruments administered were highly stable. Group means for several tests showed improvement on retest, which may indicate a practice effect, although many tests did not reach our criteria for "change." Of 962 test scores, 21 (2%) showed significant change. Most subjects were stable, with only 7% of subjects accounting for 38% of significant test-retest changes. Results indicate that the instruments assessed have sufficient reliability and stability to be used as repeated measures in clinical trials and that a small number of patients may have instability of performance as an individual characteristic.

Adult↗
PubMed2003

Classifying homicide offenders and predicting their characteristics from crime scene behavior.

A theoretical distinction between instrumental and expressive aggression was used in analyzing offender characteristics and their associations with crime scene actions in Finnish homicides. Twenty-one variables reflecting the offenders' criminal activity, previous relationships with intimates and victims, and general social and psychological adjustment were derived from files of single-offender/single-victim homicides occurring between 1980 and 1994 (n = 502). Additionally, three variables describing post-offense actions and police interview behavior were included. A multidimensional scaling procedure was used to investigate the interrelationships between the variables. A distinction between expressive and instrumental characteristics was observable in the empirical structure, which was divided into three subthemes of Instrumental, Expressive: Blood, and Expressive: Intimate. Associations between the characteristics with five previously identified subthemes of crime scene actions were computed. In addition, the subthemes of crime scene actions were related to post-offense actions and police interview behavior, with Expressive themes being associated with less denial as well as a greater likelihood of surrendering and confession. The practical usefulness for police investigations and theoretical implications of the results are discussed.

Adaptation, Psychological↗