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PubMed2003

Isotopic metrology of carbon dioxide. I. Interlaboratory comparison and empirical modeling of inlet equilibration time, inlet pressure, and ion source conductance.

We report a pilot study of high-precision differential isotope ratio measurements made on replicate samples of pure carbon dioxide using three instruments of identical manufacture. Measurement protocols were designed to explore the effects of sample size, ion source conductance, and inlet changeover equilibration time on the raw measurements. Our goal was better understanding of factors that influence these measurements in order to establish procedures for highly reproducible and accurate determinations of Reference Material (RM) isotopic compositions. Evaluation and modeling of reported data illuminated effects consistent with two instrumental memory sources--one short-lived (t((1/2)) approximately 10 s) and the other long-lived (t((1/2)) approximately 6-10 min), uncompensated by normal background measurements--that can significantly influence measurements made by the dual inlet method. These biases, proportional to the difference in isotopic compositions between the measured sample and reference gases, decrease in magnitude with increasing sample size, source conductance, and equilibration time. We observed biases as high as 0.1 per thousand per 10 per thousand difference between sample and reference gases. These memory sources may be responsible for measured delta(13)C values of RMs generally being highly reproducible within any single laboratory but less reproducible among independent laboratories. The magnitude of the bias is consistent with the ranges of delta(13)C values reported in prior laboratory intercomparisons. Uncertainties are most likely due to high and variable long-lived memory among the instruments tested.

Journal Article↗
PubMed1994

Personality characteristics of adolescents with alcoholic parents.

This study examined personality traits frequently encountered in children in families with at least one alcoholic parent. The sample investigated included 63 adolescents (32 males and 31 females) ranging in age from 12 to 19 years. Twelve self-image variables and eight aggression and anxiety variables were assessed using a battery of psychodiagnostic instruments. The results were compared with those obtained in a control group of 321 age-matched adolescents (160 males and 151 females) growing up in nonalcoholic families. Statistically significant differences between the groups were found in eight self-image variables (impulse control, emotional tone, vocational and educational goals, sexual attitudes, family relationships, psychopathology, and adjustment and depression), in six aggression variables (assault, indirect aggression, verbal aggression, irritability, suspicion, and feelings of guilt), and in both anxiety variables (i.e., anxiety as a state and anxiety as a personality trait. The findings can be functionally applied both to clinical work and to prevention programs for adolescents at risk.

Adolescent↗
PubMed2005

Performance of the Colson MAM BP 3AA1-2 automatic blood pressure monitor according to the European Society of Hypertension validation protocol.

OBJECTIVE: To evaluate the performance of the Colson MAM BP 3AA1-2 oscillometric automatic blood pressure monitor according to the validation protocol of the European Society of Hypertension, testing its suitability for self-measurement of blood pressure. The performance of the device was assessed in relation to various clinical variables, including age, gender, body mass index, arm circumference and arterial stiffness. METHOD: 33 subjects (15 men and 18 women), with a mean age of 47 +/- 10 years, were studied according to the procedures laid down in the European Society of Hypertension validation protocol. Sequential same-arm blood pressure measurements were made, alternating between a mercury standard and the automatic device. The differences among the test-control measurements were assessed and divided into categorization zones of 5, 10 and 15 mmHg discrepancy. Aortic pulse wave velocity was assessed in all subjects with a Complior device (Colson, Paris). RESULTS: The Colson MAM BP 3AA1-2 passed all three phases of the protocol for both systolic and diastolic blood pressure. The mean differences between the test and control measurements were -1.0 +/- 5.0 mmHg for systolic blood pressure and -1.1 +/- 4.1 mmHg for diastolic blood pressure. Both standard deviations are well below the 8 mmHg limit proposed by the Association for the Advancement of Medical Instrumentation. The predictive value of various clinical variables for the discrepancies was assessed by a regression model analysis, with no variable being found that independently undermined the performance of the monitor. In another regression analysis, we found a similar relation between test and control blood pressures and aortic pulse wave velocity, a widely recognized and validated index of target organ damage. CONCLUSIONS: These data show that the Colson MAM BP 3AA1-2 satisfies the quality requirements proposed by the European Society of Hypertension, demonstrating its suitability for inclusion in integrated programs of clinical surveillance based on self-measurement of blood pressure. The uniformity of its performance over a wide spectrum of clinical characteristics and the relation found with pulse wave velocity further reinforce its clinical validity.

Adult↗
PubMed1981

The effect of bromazepam on psychomotor activity and subjective mood.

The effects of short-term (acute) doses of bromazepam were studied in a double-blind trial with the aid of three dosage groups comprising a total of fifty-five healthy male medical students (who received placebo, and 1.5 mg or 3.0 mg bromazepam, respectively). Subjective well-being was recorded through self-ratings by the volunteers, and the variables of psychomotor function by standard testing instruments. In terms of subjective well-being, fatigue and decreased performance (statistically confirmed throughout) were reported by the probands in all three dosage groups after they were administered either the drug or placebo. None of the dose-effect relationships were statistically significant, although this trend was more pronounced, purely in quantitative terms, in the group that received 3 mg bromazepam than in either the placebo or the 1.5 mg bromazepam group. In the reaction time and in critical flicker-frequency (CFF) testing, the trend mentioned above was confirmed. In the attentiveness and memory span test, learning effects were statistically confirmed in equally uniform fashion. The action of the substance was again not statistically significant. It may be concluded from this that subjective, and also in part objective, fatigue and decreased performance were related to the type of trial design employed, and not, generally speaking, to the action of the substance. However, again independently of the drug's activity, statistical confirmation was obtained of improved performance and/or learning activity in three variables of the alertness testing apparatus. Variables of driving ability were not adversely affected, but--if anything--stabilized. Our investigation studied the single-dose schedules of bromazepam--viz. 1.5 mg and 3 mg--that are most commonly prescribed for patients. The subacute and personality-related effects of the drug will be the subject of a later report.

Adult↗
PubMed2006

The ALSSQOL: balancing physical and nonphysical factors in assessing quality of life in ALS.

BACKGROUND: There is no generally accepted instrument for measuring quality of life (QOL) in patients with ALS. Current instruments are either too heavily weighted toward strength and physical function or useful for the evaluation of individuals but of less utility in assessing large samples. OBJECTIVE: To develop and evaluate the psychometric properties of an ALS-specific QOL instrument (the ALSSQOL) that would reflect overall QOL as assessed by the patient and would be valid and reliable across large samples. METHODS: The ALSSQOL is based on the McGill Quality of Life Questionnaire (MQOL), modified by changes in format and by adding questions on religiousness and spirituality, items derived from interviews with ALS patients, and items identified from open-ended questions administered during the MQOL. The psychometric properties of the ALSSQOL were assessed by a prospective multicenter study in which participants completed the ALSSQOL, other instruments measuring overall QOL, and instruments assessing religiousness, spirituality, and psychological distress. RESULTS: A 59-item ALSSQOL was developed; 342 patients evaluated its psychometric properties. Completion time averaged 15 minutes. Forty-six items loaded on six factors. The ALSSQOL demonstrated concurrent, convergent, and discriminant validity for the overall instrument and convergent validity for its subscales. Analysis of individual items permitted insight into variables of clinical importance. CONCLUSIONS: This new ALS-specific quality of life instrument is a practical tool for the assessment of overall quality of life in individuals with ALS and appears to be valid and useful across large samples. Validation studies of a shortened version are now under way.

Adjustment Disorders↗
PubMed1992

Assessing alcohol problems in college students.

Alcohol abuse among college students is prevalent, yet few instruments with sound reliability and validity are available to assess these problems in this population. As part of a large, baseline assessment battery for a prospective study of offspring of alcoholics, the 27-item Young Adult Alcohol Problems Screening Test (YAAPST) was given to 490 freshmen at a large midwestern university; approximately 9 months later, 482 subjects completed the scale again. In addition to asking about such traditional problems as experiencing blackouts and driving while intoxicated, the YAAPST included specific items relating to college experiences (eg, getting into sexual situations that were later regretted, missing classes, and receiving lower grades than usual). The YAAPST was designed to assess these drinking consequences over two different time frames, lifetime and past year, and also to indicate the frequency of occurrence during the past year. Results indicated that the YAAPST is a unidimensional scale with good psychometric properties (good internal consistency and test-retest reliability). Three different approaches were used to demonstrate the validity of the YAAPST. Findings supported criterion validity (with interview-based alcohol abuse/dependence diagnoses as the criterion), concurrent validity (comparing the YAAPST with other drinking measures), and construct validity (correlating the YAAPST with etiologically relevant personality, motivational, and peer influence variables). The YAAPST is a promising screening instrument for alcohol problems in college students. It has excellent psychometric properties and the potential to provide a range of useful information to the clinician or researcher.

Adolescent↗
PubMedDate not supplied

Magnetic resonance imaging system stability: temporal variability in signal intensity, signal-to-noise, T1, and T2 measurements on a 0.15-T resistive system.

Signal intensity (SI) variability was evaluated on a 0.15-T resistive instrument using a phantom and was found to increase with time, repetition time (TR), and echo time (TE), ranging from 0.24% standard deviation (SD) over 34 min for 500/30 (TR/TE) images, to 2.1% SD over 5 days for 2000/30 images. Signal-to-noise (S/N) variability increased with time and TE but not TR and ranged from 4.2% SD over 34 min to 7.1% SD over 5 days in 500/30 images. Variability in T1 and T2 measurements on phantoms ranged from 1.8% to 4.8% SD for T1 and 3.6% to 6.5% SD for T2 in the biological range over 5 h. High reproducibility of SI, T1, and T2 measurements was demonstrated over a 6-week period in normal muscle measurements.

Biophysical Phenomena↗
PubMed1984

[Risk factors for the development of neurotic disease. A contribution to research on its psychoanalytic genesis].

As a contribution to the psychoanalytic investigation of the origins of disease a group of "Inanspruchnahmepatienten" (patients availing themselves of the services provided by psychiatric institutions) (n = 458) was compared to a group of controls (n = 448), equal to the test group with regard to age, sex, and social status, the members of which had declared to feel psychically healthy and not in need of either psychotherapy or psychiatric treatment. The objective of this comparison was to ascertain the sum total of such risk variables, designated in advance and a priori assessed, which after many years of psychoanalytic experience may be considered as highly stress-intensive life events influencing the development of a child. The risk variables in question are described and the instruments used in the recording of the documentation are delineated. Six hypotheses were examined to exclude accidental results. Patients suffering from neurotic complaints have been more frequently exposed to certain stress factors in childhood and adolescence than psychically healthy subjects. Subjects suffering from neurotic complaints (independently of the psychopathologic condition of their parents) have been more frequently exposed to certain stress factors in childhood and adolescence than psychically healthy subjects. Within a group of patients subjects with a high stress index display more severe symptoms of disorder than those with a low stress index. In patients with a high stress index incidence of neurotic symptoms is observed earlier than in patients with a low stress index. For subjects who temporarily do not feel psychically ill or in need of treatment there is nevertheless a connection between the level of the risk index and any given early symptoms having occurred during childhood and adolescence. For subjects who temporarily do not feel psychically ill or in need of treatment there is nevertheless a connection between the level of the risk index and the psychic and psychosomatic complaints registered in the list of complaints. From all six of these hypotheses accidental results could be statistically excluded or, in other words: all respective zero-hypotheses were rejected. On the basis of the here described results of the investigation it may be assumed that the variables designated, a priori assessed, and combined into a sum of risks or a risk index, were indeed of causal significance for the development of a psychosocial disposition toward risk situations which in the adult promotes the development of psychoneurotic or psychosomatic symptoms.

Adult↗
PubMed2006

Social support and change in health-related quality of life 6 months after coronary artery bypass grafting.

OBJECTIVE: We determined whether perceived social support predicted change in health-related quality of life, operationalized as change in mental health and physical functioning, 6 months after coronary artery bypass grafting (CABG). METHODS: A prospective cohort of 1164 patients undergoing first CABG was interviewed prior to hospital discharge and 6 months later. Perceived instrumental and emotional support were assessed predischarge. Change in mental health and physical functioning was calculated as the difference between 6-month and predischarge SF-36 subscale scores. Stepwise linear regression analyses controlling for prior health-related quality of life, demographics, and clinical presentation were conducted. RESULTS: A total of 1072 (1072/1164=92%) participants completed the 6-month interview; mean age 65.7 (+/-11.1) years. Frequent instrumental support predicted positive change in mental health (beta=3.27, P=.02); change scores were higher when participants had low pre-CABG mental health. Neither social support variable predicted change in physical functioning. CONCLUSIONS: Assessing perceived instrumental support may help clinicians predict post-CABG mental health. More research regarding this relationship is needed before recommending intervention efforts.

Activities of Daily Living↗
PubMed1999

The development and validation of a digital peak respiratory pressure monitor and its characteristics in healthy human subjects.

A digital peak respiratory pressure (DPRP) monitor for determining maximum inspiratory pressure (MIP) and maximum expiratory pressure (MEP) was developed using a pressure transducer and an analog to digital converter. It was calibrated using a mercury manometer. Human studies were conducted in healthy young adults in order to determine within-subject and inter-individual variability, as well as diurnal variations and gender differences in maximal respiratory pressures. The calibration studies for the instrument indicated that the instrument recorded accurate pressures, with little temporal drift. Within-subject variability was generally low while inter-individual variability was higher and significant. Gender differences were similar to those recorded in literature for other racial groups. The DPRP monitor described is inexpensive, accurate and portable, making it ideal for use at the patient's bedside.

Adult↗
PubMed1997

Lumbar stenosis: indications for fusion with and without instrumentation.

Although the efficacy of posterior decompression for symptomatic lumbar stenosis that is recalcitrant to conservative therapy is well proven, uniform agreement on the need for simultaneous arthrodesis is lacking. The variability in the rate of lumbar fusion with and without instrumentation has been attributed to a number of factors: advances in surgical technique; rapid development of instrumentation; radiographic advances in the diagnosis of disease entities of the lumbar spine; evolution in our understanding of bone healing; improved pre- and postoperative care; aggressive rehabilitation; patient compensation; hospital and surgeon reimbursement; better education of residents, fellows, and practicing neurosurgeons; and, most important, the lack of clear indications based on defined diagnostic categories. Based on review of the literature and their experience at the Barrow Neurological Institute, the authors have attempted to define indications for lumbar fusion with or without instrumentation based on defined diagnostic categories. Clear indications for fusion include trauma, tumor, or infection with two- or three-column injury, iatrogenic instability, and isthmic spondylolisthesis. Relative indications for fusion include degenerative spondylolisthesis, radiographically proven dynamic instability with pain or neurological findings, adult scoliosis, and mechanical back pain. Fusion is rarely indicated with discectomy, abnormal radiographs without appropriate findings (such as degenerative disc disease), facet joint syndrome, failed back surgery, or stable spinal stenosis.

Journal Article↗
PubMed1977

A study of the variability of setting a fully adjustable gnathologic articulator to a pantographic tracing.

The purpose of this study was to determine the variability encountered in setting a fully adjustable articulator to a pantographic tracing produced by the same articulator. It was shown that adjustments for top wall, vertical axis, and rear wall were of the greatest magnitude. The practical significance of this investigation lies in the data base that it provides for further analysis of tracings produced in a similar manner. The results show an inherent system variability and that mechanical and operator errors were involved only in the actual setting of the instrument. This problem deserves further research into the exact causes of the variability and the effects that the various adjustments have upon one another. Continued efforts in this vein can only lead to further elucidation of the complexities involved in mandibular movement and capture of such movements by mechanical means.

Dental Articulators↗
PubMed1996

Sexuality and fertility concerns of dialysis patients.

OBJECTIVES: The purposes of this study were to identify the frequency of sexual and fertility dysfunctions and satisfactions experienced by patients on dialysis therapy and their relationships to life quality variables, and whether patients desired to or received instruction regarding possible sexuality and fertility problems. DESIGN: The study used a descriptive, survey design. SAMPLE/SETTING: A convenience sample was obtained from 7 hospital-based dialysis centers in the state of Iowa. METHOD: A mailed questionnaire, composed of 7 instruments, was used to survey demographic and medical variables, activity level, fertility and sexual dysfunction, intimacy patterns, sexual attitudes, life and health quality, and satisfaction with sexual relationships of patients treated with dialysis therapy. RESULT: Sixty-five percent of the subjects (n = 135) were dissatisfied with their sexual relationship, 40% no longer engaged in intercourse or sexual activity, yet only 25% had received instruction regarding possible dysfunctions. Subjects satisfied with their sexual relationships differed significantly (p < .05) from those who were dissatisfied in activity level, intimacy patterns, and life and health quality with frequency of arousal, orgasm, and acceptance of partner's advances significantly related to sexual satisfaction. CONCLUSION: The standards of care identified by the American Nephrology Nurses' Association regarding sexuality had not been achieved in the sample measured.

Adult↗
PubMed2000

Intraoperative PAR corneal topography system (CTS): comparison of its keratometric readings to manual keratometer, auto-keratometer, EyeSys Corneal Analysis system, and slit lamp PAR CTS in healthy eyes.

PURPOSE: To compare the keratometric readings obtained from Intraoperative PAR Corneal Topography System (IOPAR) to those produced by manual keratometer (Mnl-Km), autokeratometer (Auto-Km), EyeSys CAS (EyeSys Corneal Analysis System) and slit lamp PAR CTS in healthy eyes. METHODS: All instruments were calibrated prior to use and only data from the best image obtained was used for statistical analysis. Simulated keratometry readings obtained from the central 3-mm zone of the corneas by IOPAR, including flat (K1) and steep (K2) keratometry readings, average keratometric power (AK), astigmatism (As) (difference between steep and flat keratometry readings) and the axis of the steep meridian (Ax) were compared to those from four other units. The latter units were also compared among themselves. Statistical analysis was done for right and left eyes separately. For each variable, average differences between the measurements taken from pairs of instruments were estimated, with corresponding 95% confidence intervals. The degree of agreement between pairs of instruments on individual measurements was additionally assessed, via the use of "Bland-Altman"-type plots, and estimates of the proportion of cases achieving satisfactory agreement. Additionally, for every variable, the average of the measurements taken from the different instruments were compared. RESULTS: Forty-five (22 right and 23 left) normal corneas of 26 volunteers were examined. On the average, IOPAR tended to measure K1 higher than slit lamp PAR CTS system. Because K2 measurements taken by the IOPAR were higher than that of all other instruments, the As measurements, on the average, were also higher than that of others, with the exception of the PAR CTS. For the same reasons, the IOPAR produced average AK readings that were higher than those taken by EyeSys CAS and PAR CTS. When the individual measurements taken by the IOPAR were compared with each of the other units, according to the arbitrary designation of satisfactory agreement within +/-0.5 D (for K1, K2, AK, and As) and +/-20 degrees (for Ax), for almost all parameters, proportion of differences that were within the agreement range varied from 0.33 to 0.82, with wide confidence intervals (confidence interval lower limits ranging from 0.20 to 0.61 and upper limits ranging from 0.62 to 0.94). CONCLUSIONS: IOPAR is a clinically useful topographic system, producing qualitative and quantitative data in the operating environment that, in normal corneas, on the average, matches those produced by the other units in the clinic. When individually analyzed, its keratometric measurements may show greater variations with respect to other units. Further studies with multiple examiners, in corneas with high or irregular astigmatism are required to establish its reproducibility and efficacy.

Adult↗
PubMed1994

Prediction of recreational therapy behavior of hospitalized adolescents from a behavior classification instrument.

The purpose of this study was to estimate the validity of an instrument of the Adolescent Behavioral Classification Project in predicting behavior patterns of emotionally disturbed adolescents in an inpatient setting. Subjects (n = 126) were adolescents admitted to a state residential treatment unit across a period of 35 months. Predictor variables were scores on 17 or 25 factors of the instrument from both adolescents' own responses and their mothers' responses on their behalf. Criterion variables were 10 recreational therapy factors, especially 4 temporally stable factors, and length-of-time in treatment. 3 phases of the project were (I) behavior during initial stages of the therapy, (II) behavioral change after 3 months of therapy, and (III) length-of-time in treatment. In Phase I, both mothers' and adolescents' responses produced significant correlations with criteria; however, in Phase II only the adolescent students' 25 ABCP factors predicted behavioral change. In Phase III, adolescents' responses but not their mothers' responses classified the adolescents by length-of-time in treatment.

Adolescent↗
PubMed2005

Development and preliminary validation of a systemic lupus erythematosus-specific quality-of-life instrument (SLEQOL).

OBJECTIVES: Systemic lupus erythematosus (SLE), a chronic illness with an unpredictable and variable course, profoundly affects the quality of life (QOL). General health questionnaires are used to assess QOL in SLE, but a disease-specific instrument could offer enhanced responsiveness and content validity. We detail the steps we took to develop and validate a new SLE-specific QOL instrument, SLEQOL. METHODS: Rheumatology professionals nominated items that they felt were important determinants of QOL of SLE patients. One hundred SLE patients were asked to assess the importance and frequency of occurrence of these items and to suggest those that had not been listed. Item reduction was performed using Rasch model and factor analyses to create a new questionnaire in English. This final questionnaire was administered to a cohort of 275 patients to study its psychometric properties. RESULTS: Fifty-one items covering a wide range of QOL concerns were identified. The patients' responses led to the elimination of 11. The new questionnaire of 40 items was found to have Cronbach's alpha of 0.95 and to consist of eight domains covering physical, mental and social QOL issues. It has good test-retest reliability, poor to fair cross-sectional correlation with the SF-36, with poor correlation with lupus activity or damage indices. The SLEQOL was more responsive to change than the SF-36. CONCLUSIONS: We have developed a new 40-item SLEQOL in English and showed that it is valid for use in SLE patients in Singapore. It offers better content validity and responsiveness to change than the SF-36.

Activities of Daily Living↗
PubMed2004

Upper-body strength and power assessment in women using a chest pass.

Finding assessment methods that are reliable, valid, and easy to administer is important, especially when assessing large numbers of athletes. The purpose of this research therefore was to investigate whether assessment of the upper body using the chest pass throw was significantly related to strength and power as measured using the bench press. The chest pass distance of 12 experienced netball players was measured; thereafter, their bench press 1 repetition maximum and various kinematic and kinetic variables were calculated from a 10-kg bench press throw performed on an instrumented Smith machine. Pearson correlation coefficients were used to establish the relationship between the strength/power variables and the chest pass. Of the kinematic and kinetic variables calculated from the bench press throws, impulse and power were the variables most highly correlated to chest pass distance (r = 0.775-0.810), whereas the measures of initial force production (F30ms and F100ms) were the lowest (r = 0.082-0.105). Four variables had a greater than 50% (R2) shared variance with the netball chest pass-impulse, peak power, mean power and maximal strength. Power and impulse are strong predictors of chest pass performance; however, the value of the chest pass as an assessment tool to map strength and power changes in an athlete needs to be investigated using a training study approach.

Adult↗
PubMed1985

Data analysis of long-term blood pressure monitoring.

Long-term blood pressure monitoring provides a large quantity of data with a wide inter-individual or inter-group variability. The conventional "mean/standard deviation" approach to data analysis is a relatively insensitive instrument for detecting circadian differences in blood pressure profile, mainly because the mean and the variability around the mean are processed separately. The proposed Standardized Systolic and Diastolic Scoring (SSDS) method enhances the analytical possibilities. Preliminary evaluation of the SSDS method using data obtained in an anti-hypertensive drug trial suggests clinical relevance.

Ambulatory Care↗