SEARCH · PubMed Health

Results for “Consistency”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 289 records · Page 16Linked to original sources

PubMed1983

Consistency and signal strength of respiratory neuronal activity.

The concerns of this study are taxonomic. We demonstrate a defining characteristic of respiratory neuronal activity. This characteristic is the degree or size of the respiratory component in the activity of a respiratory cell. The essential feature of respiratory activity is that it occurs in phase with some portion of the respiratory cycle. Therefore, neuronal activity can be arranged within a matrix in which the columns are fractions of the respiratory cycle and the rows are breaths and, as Netick and Orem (10) have shown, this matrix can be analyzed with an analysis of variance to determine whether the activity contains a respiratory component. However, the analysis of variance indicates nothing about the size of a statistically significant respiratory component. We hypothesized that the size of the respiratory component in the activity of different respiratory cells differed among cells but was a stable characteristic of any given cell. The index used to quantify the degree of respiratory activity was eta 2, the proportion of the total variance of the activity of a respiratory neuron consisting of the variance occurring across fractions of the respiratory cycle. This index theoretically depends on a) the range of activity levels across a respiratory cycle and the dispersion of activity levels over this range (parameters signifying the strength of the respiratory signal) and b) the variability in the activity of the cell across breaths (a parameter signifying the consistency of the respiratory activity). Theoretically, eta 2 values can vary from 0.0 to 1.0 indicating, respectively, that none or all of the variability in the activity of a cell across breaths is accounted for by a respiratory effect. eta 2 was used to analyze the size of the respiratory component in the activity of 32 medullary respiratory neurons recorded during nonrapid eye movement (NREM) sleep in chronic cats. These different respiratory cells had activity patterns with eta 2 values ranging from 0.1 to 0.9. However, the activity of a given cell produced eta 2 values that were consistent from sample to sample. Therefore, the eta 2 value of the activity of a cell was a defining, stable characteristic of that cell. The eta 2 values of the activity of the cells were strongly correlated with the consistency of their discharge pattern from breath to breath (r x,y = 0.975).(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗

PubMed1995

Effects of protein deficiency and diet consistency on the parotid gland and parotid saliva of rats.

Protein deficiency results in an increased susceptibility to dental caries, suggesting that oral host-defense properties are compromised. An important component of oral host defense is salivary gland function, which is affected by both protein deficiency and diet consistency. This study describes the effects on rat parotid gland growth and secretory function induced by feeding rats diets of normal (20%) or moderately low (7%) protein content, provided in either a powdered or solid form. In addition, since protein deficiency may result in a secondary zinc deficiency which, in turn, may affect salivary gland function, the effects of these diets on liver zinc concentration were also measured. From 22 to 47 days of age, rats (18/group) were fed the following diets: normal protein, powdered; normal protein, solid; low protein, powdered; and low protein, solid. With each diet consistency, liver zinc was higher for the normal protein group. Within each protein level, liver zinc was higher for the solid diet. This latter observation suggests that food mastication and the resultant stimulation of salivary gland function may also play a role in zinc metabolism. With the normal-protein diet, parotid gland weight was higher for the solid diet; with the low-protein diet, parotid gland weight was similar for both consistencies and did not differ from that of the group fed the "normal protein, powdered" diet. For both consistencies, parotid saliva protein concentration was greater for malnourished rats.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed2006

Particulate matter properties and health effects: consistency of epidemiological and toxicological studies.

Identifying the ambient particulate matter (PM) fractions or constituents, critically involved in eliciting adverse health effects, is crucial to the implementation of more cost-efficient abatement strategies to improve air quality. This review focuses on the importance of different particle properties for PM-induced effects, and whether there is consistency in the results from epidemiological and experimental studies. An evident problem for such comparisons is that epidemiological and experimental data on the effects of specific components of ambient PM are limited. Despite this, some conclusions can be drawn. With respect to the importance of the PM size-fractions, experimental and epidemiological studies are somewhat conflicting, but there seems to be a certain consistency in that the coarse fraction (PM10-2.5) has an effect that should not be neglected. Better exposure characterization may improve the consistency between the results from experimental and epidemiological studies, in particular for ultrafine particles. Experimental data indicate that surface area is an important metric, but composition may play an even greater role in eliciting effects. The consistency between epidemiological and experimental findings for specific PM-components appears most convincing for metals, which seem to be important for the development of both pulmonary and cardiovascular disease. Metals may also be involved in PM-induced allergic sensitization, but the epidemiological evidence for this is scarce. Soluble organic compounds appear to be implicated in PM-induced allergy and cancer, but the data from epidemiological studies are insufficient for any conclusions. The present review suggests that there may be a need for improvements in research designs. In particular, there is a need for better exposure assessments in epidemiological investigations, whereas experimental data would benefit from an improved comparability of studies. Combined experimental and epidemiological investigations may also help answer some of the unresolved issues.

Cardiovascular Diseases↗

PubMed2003

Consistency of linkage results across exams and methods in the Framingham Heart Study.

BACKGROUND: The repeated measures in the Framingham Heart Study in the Genetic Analysis Workshop 13 data set allow us to test for consistency of linkage results within a study across time. We compared regression-based linkage to variance components linkage across time for six quantitative traits in the real data. RESULTS: The variance components approach found 11 significant linkages, the regression-based approach found 4. There was only one region that overlapped. Consistency between exams generally decreased as the time interval between exams increased. The regression-based approach showed higher consistency in linkage results across exams. CONCLUSION: The low consistency between exams and between methods may help explain the lack of replication between studies in this field.

Adult Children↗

PubMed2005

Women and postfertilization effects of birth control: consistency of beliefs, intentions and reported use.

BACKGROUND: This study assesses the consistency of responses among women regarding their beliefs about the mechanisms of actions of birth control methods, beliefs about when human life begins, the intention to use or not use birth control methods that they believe may act after fertilization or implantation, and their reported use of specific methods. METHODS: A questionnaire was administered in family practice and obstetrics and gynecology clinics in Salt Lake City, Utah, and Tulsa, Oklahoma. Participants included women ages 18-50 presenting for any reason and women under age 18 presenting for family planning or pregnancy care. Analyses were based on key questions addressing beliefs about whether specific birth control methods may act after fertilization, beliefs about when human life begins, intention to use a method that may act after fertilization, and reported use of specific methods. The questionnaire contained no information about the mechanism of action of any method of birth control. Responses were considered inconsistent if actual use contradicted intentions, if one intention contradicted another, or if intentions contradicted beliefs. RESULTS: Of all respondents, 38% gave consistent responses about intention to not use or to stop use of any birth control method that acted after fertilization, while 4% gave inconsistent responses. The corresponding percentages for birth control methods that work after implantation were 64% consistent and 2% inconsistent. Of all respondents, 34% reported they believed that life begins at fertilization and would not use any birth control method that acts after fertilization (a consistent response), while 3% reported they believed that life begins at fertilization but would use a birth control method that acts after fertilization (inconsistent). For specific methods of birth control, less than 1% of women gave inconsistent responses. A majority of women (68% or greater) responded accurately about the mechanism of action of condoms, abstinence, sterilization, and abortion, but a substantial percentage of women (between 19% and 57%) were uncertain about the mechanisms of action of oral contraceptives, intrauterine devices (IUDs), Depo-Provera, or natural family planning. CONCLUSION: Women who believe that life begins at fertilization may not intend to use a birth control method that could have postfertilization effects. More research is needed to understand the relative importance of postfertilization effects for women in other populations, and in relation to other properties of and priorities for birth control methods. However, many women were uncertain about the mechanisms of action of specific methods. To respect the principles of informed consent, some women may need more education about what is known and not known about the mechanisms of action of birth control methods.

Journal Article↗

PubMed2005

Internal consistency reliability is a poor predictor of responsiveness.

BACKGROUND: Whether responsiveness represents a measurement property of health-related quality of life (HRQL) instruments that is distinct from reliability and validity is an issue of debate. We addressed the claims of a recent study, which suggested that investigators could rely on internal consistency to reflect instrument responsiveness. METHODS: 516 patients with chronic obstructive pulmonary disease or knee injury participating in four longitudinal studies completed generic and disease-specific HRQL questionnaires before and after an intervention that impacted on HRQL. We used Pearson correlation coefficients and linear regression to assess the relationship between internal consistency reliability (expressed as Cronbach's alpha), instrument type (generic and disease-specific) and responsiveness (expressed as the standardised response mean, SRM). RESULTS: Mean Cronbach's alpha was 0.83 (SD 0.08) and mean SRM was 0.59 (SD 0.33). The correlation between Cronbach's alpha and SRMs was 0.10 (95% CI -0.12 to 0.32) across all studies. Cronbach's alpha alone did not explain variability in SRMs (p = 0.59, r2 = 0.01) whereas the type of instrument was a strong predictor of the SRM (p = 0.012, r2 = 0.37). In multivariable models applied to individual studies Cronbach's alpha consistently failed to predict SRMs (regression coefficients between -0.45 and 1.58, p-values between 0.15 and 0.98) whereas the type of instrument did predict SRMs (regression coefficients between -0.25 to -0.59, p-values between <0.01 and 0.05). CONCLUSION: Investigators must look to data other than internal consistency reliability to select a responsive instrument for use as an outcome in clinical trials.

Clinical Trials as Topic↗

PubMed2002

Reporting consistency in systemic lupus erythematosus patients: how reliable are patient histories?

Systemic lupus erythematosus (SLE) patients are frequently seen by multiple physicians and at multiple times. In each instance, most of the information important in clinical decision-making is gathered from the patient. There are no studies looking at reporting consistency of certain aspects of SLE patients' history. We studied this by administering the same nine-item questionnaire 4 months apart to the same cohort of SLE patients. In addition, a retrospective chart review was done to correlate the information obtained by prospective questioning and with that on the charts. Our results showed overall good consistency in the areas of general medical history, SLE-specific history and social history. The information gathered by the chart review, in general, went in parallel with that obtained by prospective questioning. This was also true for the poor correlation observed in the family history questions. Many studies and databases depend rather heavily on patient reporting and the quality of this information is usually not substantiated. Our study suggests that, even though SLE patients are generally consistent reporters of certain aspects of their histories, family history information provided is frequently not consistent with previous reporting.

Cohort Studies↗

PubMedDate not supplied

Contraceptive use and consistency in U.S. teenagers' most recent sexual relationships.

CONTEXT: Most U.S. teenage pregnancies are unintended, partly because of inconsistent or no use of contraceptives. Understanding the factors associated with contraceptive use in teenagers' most recent relationships can help identify strategies to prevent unintended pregnancy. METHODS: Data on 1,468 participants in Waves 1 and 2 of the National Longitudinal Study of Adolescent Health who had had two or more sexual relationships were analyzed to assess factors associated with contraceptive use patterns in teenagers' most recent sexual relationship. Odds ratios were generated through logistic regression. RESULTS: Many relationship and partner characteristics were significant for females but nonsignificant for males. For example, females' odds of ever, rather than never, having used contraception in their most recent relationship increased with the duration of the relationship (odds ratio, 1.1); their odds were reduced if they had not known their partner before dating him (0.2). The odds of consistent use (vs. inconsistent or no use) were higher for females in a "liked" relationship than for those in a romantic relationship (2.6), and for females using a hormonal method instead of condoms (4.5). Females' odds of consistent use decreased if the relationship involved physical violence (0.5). Among teenagers in romantic or "liked" relationships, the odds of ever-use and of consistent use were elevated among females who had discussed contraception with the partner before their first sex together (2.9 and 2.1, respectively), and the odds increased among males as the number of presexual couple-like activities increased (1.2 for each). CONCLUSIONS: Teenagers must use contraception consistently over time and across relationships despite pressure not to. Therefore, they must learn to negotiate sexual and contraceptive decisions in each relationship.

Adolescent↗

PubMed2001

Applicability of personality disorder criteria in late adolescence: internal consistency and criterion overlap 2 years after psychiatric hospitalization.

We examined internal consistency and criterion overlap of DSM-III-R personality disorder criteria in late adolescence, 2 years after psychiatric hospitalization. A total of 60 adolescents were assessed with the Personality Disorder Examination. Within-category cohesiveness (internal consistency) was evaluated by coefficient alpha and mean intercriterion correlation (MIC). Between-category criterion overlap was evaluated by examining intercategory mean intercriterion correlations (ICMIC) between all pairs of disorders. Internal consistency was low, with alpha less than .70 for all except borderline and dependent personality disorders. For most disorders, MIC values were higher than ICMIC values. Our findings suggest that personality disorder criteria sets have limited internal consistency in older adolescents. Although the criteria for most personality disorders correlate better with each other than with the criteria for other personality disorders, suggesting some degree of discriminant validity, comparison of these results with a similar analysis performed shortly after hospital admission raises questions about personality disorder construct validity during adolescence.

Adolescent↗

PubMed2006

Irreducible representation for nucleotide sequence physical properties and self-consistency of nearest-neighbor dimer sets.

A compact representation of usual DNA/RNA four-nucleotide sets based on molecular affinity classes is proposed. In a geometrical correspondence to this formulation, it follows that intrinsic tetrahedral symmetry correlates nucleotide properties. This representation also leads to a proper decomposition frame for any sequence-dependent physical expectation. Thermodynamic and other physical properties of nucleotide sequences are most often stated within the scope of nearest-neighbor models and decomposed in terms of dimer properties. The inverse problem of obtaining dimer set properties is, however, well known to be ill-posed due to sequence composition closure relations. Analysis of the dimer set composition and structure within the novel tetrahedral formulation provides important self-consistency relations, solving the ill posed nature of the original formulation. As an applied example, we analyze DNA oligomer duplex free energy data available on the literature. It is shown that imposition of stringent self-consistency relations does not decrease fit quality to the experimental data set. On the other hand, an improved dimer set with physically consistent free energies is obtained. Meaningful corrections to previous determinations are found when the self-consistent set is applied to calculate free energies for sequences with composition order bias.

Base Sequence↗

PubMed2003

Tolerability and consistency of effect of zolmitriptan nasal spray in a long-term migraine treatment trial.

OBJECTIVES: To primarily assess the tolerability of zolmitriptan (Zomig) nasal spray 5mg in the long-term treatment of migraine, as well as determine efficacy and consistency of effect over time (up to 1 year). METHODS: This randomised, double-blind-to-dose, parallel-group, multicentre study was designed as a two-phase, crossover trial with a total duration of 1 year. In the pre-crossover phase, 1,093 patients aged 18-65 years with an established diagnosis of migraine with or without aura received intranasal zolmitriptan 5, 2.5, 1 or 0.5mg for the treatment of mild, moderate or severe migraine attacks. When a headache persisted or recurred, a second dose of zolmitriptan nasal spray (or other approved escape medication) was permitted 2 hours post-administration but no later than 24 hours after the first dose. In the post-crossover phase, once a placebo-controlled, dose-finding study had established 5mg as the dose with the optimal clinical utility, all patients were crossed over under blinded conditions to receive this dose. As this was primarily a safety study, the primary endpoints for the study were the incidence and nature of all serious adverse events (at any time before or after administration) and nonserious adverse events (within 24 hours of administration), as well as the incidence of clinically significant abnormalities in either ECG or haematology and clinical chemistry parameters. Nose and throat examinations were performed before and after the study at 30 predetermined trial centres. Other endpoint measures included headache response rate, pain-free assessments, reduction in headache intensity, time to resumption of normal activities and consistency of headache response. Efficacy rates were measured in 90-day intervals up to a period of 360 days. RESULTS: Zolmitriptan nasal spray 5mg was well tolerated, with only 1.9% of patients withdrawing from the 12-month long-term trial because of adverse events. Adverse events occurred in 22.1% of attacks treated with zolmitriptan nasal spray 5mg, and the majority were of short duration and mild or moderate intensity. Serious adverse events occurred in 0.2% of attacks treated with zolmitriptan nasal spray 5mg. There was no evidence of increased incidence of adverse events with increasing duration of treatment. Nasopharyngeal adverse events were reported in 5.5% of attacks treated with zolmitriptan nasal spray 5mg. Again, events were generally transient and of mild intensity. For the 1,093 patients who treated 13,806 attacks during the pre-crossover phase, headache response rates at 2 hours over all attacks were 73.2%, 70.5%, 49.9% and 41.5% for zolmitriptan nasal spray 5, 2.5, 1 and 0.5mg, respectively. Pain-free rates at 2 hours over all attacks were 51.5%, 48.1%, 24.7% and 21.8%, respectively. For the 783 patients receiving the 5mg dose in either the pre- or post-crossover phases, the 2-hour headache response rates were 72.9%, 74.4%, 74.6% and 74.1% for the four 90-day periods between day 0 and day 360. Normal activities were resumed within 2 hours in 60.4% of attacks. Long-term usage of zolmitriptan nasal spray 5mg was also associated with a consistently effective response, with 57.8% of patients experiencing a 2-hour headache response in over 75% of attacks. The majority of patients (70.3%) rated their overall satisfaction with zolmitriptan nasal spray 5mg as good or excellent. CONCLUSION: Zolmitriptan nasal spray 5mg provides good tolerability and efficacy in long-term use in a clinical setting, with consistently high 2-hour headache and pain-free rates. This combination of benefits translates to high patient satisfaction with this formulation of zolmitriptan.

Administration, Intranasal↗

PubMed1975

Relationship between auditory discrimination, articulation stimulability, and consistency of misarticulation.

A study was conducted to measure the relationship between auditory discrimination, articulation stimulability, and consistency of misarticulation. Data were based on the Carter-Buck Nonsense-Syllable Imitation Test for stimulability of /s/, the McDonald Deep Test of Articulation which measured consistency of misarticulation of /s/, and the Farquhar-Bankson In-depth Test of Auditory Discrimination which measured external and internal auditory discrimination of /s/. Ss were 25 kindergarten and first grade children with normal hearing and intelligence. No S had received any speech therapy. Each S misarticulated a minimum of three /s/ items on the McDonald Screening Test of Articulation. No more than one phoneme was misarticulated in addition to misarticulation of /s/. A significant correlation between the child's ability to discriminate his own production of /s/ (internal or self-monitoring) and the consistency of misarticulation of /s/ was obtained, as well as one between the consistency of misarticulation of /s/ and the stimulability of /s/. No statistically significant correlations were found between the other variables. A low nonsignificant correlation was found between the stimulability of /s/ and internal discrimination abilities. Different types of discrimination tasks were of varying difficulty. Performance on external discrimination items was better than for internal discrimination items.

Auditory Perception↗

PubMed1996

Temporal consistency and stability of three scales for measuring stress in adults.

We investigated the 30-min. temporal consistency and temporal stability of three focal scales for measuring stress: the Cognitive Anxiety Scale-State, the Focusing Inventory Scale-State, and the Somatic Symptom Scale-State. These scales are applicable for individually measured reduction in stress in research on outcome with older adolescents and adults. All possess excellent internal consistency. All manifested significant temporal consistency and good to excellent temporal stability over 30 min. in a nonclinical sample of 60 undergraduates. Small significant differences in means on the Cognitive Anxiety Scale-State and the Somatic Symptom Scale-State were noted. The phenomenological states associated with stress were stable and consistent over 30 min., the optimal time interval used in research on stress.

Adult↗

PubMed1998

Consistency of hand use and accidents with injury.

In this study, we examined the relationship between the consistency of hand use and the self-reported incidence of accidents with injuries which required medical care in groups of university students (n = 23 for each group). To do this, we adopted a scoring procedure for the Briggs-Nebes Handedness Scale that permitted us to classify individuals as consistent or inconsistent in the use of their hands. We observed that the inconsistent group was 6.12 times more likely to have experienced accidents with injury that required medical care than the consistent group. These data have implications for the literature on handedness classification and accidents. Collectively, these limited data underscore the need to pay attention to the consistency of hand use in research on handedness, health, and longevity.

Accidents↗

PubMed1995

The time-course of global precedence and consistency effects.

The global precedence effect refers to the finding that global aspects of a scene are processed more rapidly than local detail in the scene. In experiments with large Hs and Ss (global stimuli) made up of small Hs and Ss (local stimuli), choice reaction time (RT) to the global letters is shorter than RT to the local letters (global precedence effect). In addition, RT for local letters is shorter when the local letters are the same as the global letter (consistency effect). We sought to determine the time course of the global precedence and consistency effects by delaying the global information relative to the local information. In Experiment I, the middle cross-bar of the global letter (S or H) was presented followed by the rest of the global letter at delays of 0, 48, 80, 160, 320 and 640 ms. The results indicated that the global precedence effect was obtained at delays < 48 ms and local precedence effects are obtained at delays > 80 ms. Consistency effects were found in the absence of global precedence effects, but only at delays of 48 and 80 ms. Experiment II was a replication with delays of 16, 32, 48, 64, 80, and 96 ms. The results of this experiment were in agreement with those of Experiment I. These findings offer support for the notion that the consistency effect is mediated by a higher level process than is the global precedence effect.

Adult↗

PubMed1995

Effect of amylase treatment on the consistency of cooked, fermented oat bran porridge.

Oat bran porridges were cooked and fermented at 5, 10, 15, and 20% solids (as is basis). Cooking was carried out on gas stove and viscograph. Supplementation with malt flour at 0.1, 0.25, 0.5, 0.75, and 1%. Cooked oat bran porridge was inoculated with fresh yoghurt and fermented 18 h overnight in an incubator at 42 degrees C. Falling number values were made to estimate the effects of amylase treatments by addition of malt flour on oat bran slurry when heated in an aqueous suspension. Pasting properties were observed with the viscograph and consistency measurements were made with Bostwick consistometer. The falling number method was not suitable for consistency measurements due to wide variations in values obtained. Enzymatic additions reduced the consistency of porridge with an increase in flowability during measurements. The peak heights obtained from the viscograms reduced proportionally with an increase in malt flour supplementation. The desirability of a product with higher energy values and a sufficiently low consistency that is spoonable was possible with cooked, fermented oat bran porridge.

Amylases↗

PubMed1996

[Behavioral consistency when parents drive their children to preschool].

How drivers signal, park, escort their children across a street to a preschool, and depart was videotaped unobtrusively for 39 days, to test for consistency of driver behavior and children's crossing behavior. Data were analyzed for 17 pairs of drivers and children, observed more than ten times under identical conditions. Frequency of identical actions was analyzed on the basis of category systems, whereby a sequence of behavior was broken down into several items. A variety of individual differences and inter-behavioral differences in consistency were detected, and in general drivers were more consistent than children. Drivers' signals and accompanying of children were somewhat inconsistent, while some of their choice behaviors were very stable. Inconsistent behavior was discussed in terms of the lack of or insufficient specification of drivers' and children's schemas. Repeated naturalistic observation can not only identify behavioral consistency and reveal the structure of relevant schemas in daily life but also can predict behavior.

Adult↗

PubMedDate not supplied

Consistency of handwriting in early elementary students.

OBJECTIVE: The purpose of this longitudinal study was to examine the consistency of handwriting in children from the beginning of kindergarten to the middle of the first-grade year. Consistency was defined as retaining the same qualitative performance and relative ranking over time. METHOD: Ninety-three children were tested at the beginning of the kindergarten year and again in the middle of the first-grade year on the Scale of Children's Readiness In PrinTing (SCRIPT). Data were analyzed with a repeated measures analysis of variance (ANOVA) (3 performance groups [lower, middle, upper] x 2 grades) followed by a Tukey's HSD post hoc analysis. An analysis of the change in performance of individual children also was conducted. RESULTS: The main effects and the interaction in the ANOVA were significant. Post hoc analysis for grade demonstrated that both the middle and the lower performing groups showed a significant improvement from kindergarten to first grade, whereas the upper performing group remained unchanged. Post hoc analysis found significant differences among all three performance groups in kindergarten. In first grade, the lower performing group continued to score significantly lower than the middle and upper performing groups, whereas the middle and upper performing groups were not significantly different. Analysis of individual data revealed that 60% of the students were consistent in their performance from kindergarten to first grade. CONCLUSION: The correlation between kindergarten SCRIPT scores and first-grade SCRIPT scores provides initial evidence that a moderately consistent pattern of handwriting performance exists. Students with low- and middle-ranked handwriting skills show relatively similar improvement over time, whereas change for students ranked high is limited.

Analysis of Variance↗