Biomedical subjects

P Liehr

Publications and source records attributed to P Liehr.

24 records · Page 2Linked to original sources

PubMedDate not supplied

Assessing agreement between clinical measurement methods.

Nursing practice and research often require the use of one measurement method in place of another, creating the need to know how well one clinical measurement method approximates another. The usual statistical analyses for assessing agreement between measurement methods are the correlation coefficient and the paired t test. This article suggests that these statistical methods do not address the question of agreement. It proposes the limits of agreement as a more informative analysis when a researcher is interested in replacing one measurement method with another. The application of limits of agreement analysis to assess repeatability of one measurement method is also introduced.

Blood Pressure Determination↗

PubMedDate not supplied

Psychometric testing of the adolescent version of the Cook-Medley hostility scale.

Hostility, a phenomenon that has been linked to cardiovascular disease and all-cause mortality, is often measured by the Cook-Medley hostility (Ho) scale. Although there is an adolescent version of the Ho scale, it has had little testing with only Anglo-American samples. This pilot study tested the reliability and validity of the adolescent version of the Ho scale with a multiethnic sample of adolescents. Sixty adolescents participated. Reliability was measured using Chronbach's alpha. The Ho scale was correlated with the Speilberger State-Trait Anger Expression Inventory (1988) scales to determine concurrent validity. A factor analysis assessed construct validity; content validity was assessed by analyzing tape-recorded descriptions of a circumstance that provoked anger, as remembered by each adolescent. Internal consistency reliability was .75. The hostility measure was most highly correlated with anger expression (r = .62, p = .000) and trait anger (r = .50, p = .000). The factor analysis generated three factors (suspicious alienation, cynical aggression and justified mistrust), that accounted for 34.5% of the variance. The content analysis resulted in five anger-provoking themes: aggression, unfulfilled personal expectations, mistrust/lying, criticism of effort, and rejection. The majority of items in the scale (74%) were related to one of the themes.

Adolescent↗

PubMedDate not supplied

Strategies for combining and scaling sexual maturity indicators: the Heartfelt Study.

PRIMARY OBJECTIVE: To identify the best variable or combination of sexual maturity variables to use in investigations of adolescent health, and explore possible re-scaling of five-stage sexual maturity stages into dummy variables' ('advanced'/'delayed'). RESEARCH DESIGN: Cross-sectional. SUBJECTS: Tri-ethnic sample of 384 US adolescents 11-16 years of age (Heartfelt Study). METHODS: Sexual maturity variables are genital. breast and pubic hair stages obtained by clinical examination by nurse practitioners, testes size, menarche and age at menarche. RESULTS: Principal factor analysis of sexual maturity variables, height and age, revealed high commonality among the variables, as no more than a single factor appeared in 27 of 28 factor analyses (by sex and age groups). Genital stage (boys) and breast stage (girls) were most highly related to the first principal factor independent of age and ethnicity. ANOVA of 'key variables' indirectly reflecting endocrine function suggested that some stages could be combined. CONCLUSIONS: A single variable should suffice to describe sexual maturity at the studied ages, or variables could be combined in a (unstandardized) sexual maturity index (SMI): SMI (Girls)=0.998 x BREAST+0.900 x PUBIC HAIR + 1.815 x YEARS SINCE MENARCHE. SMI (Boys)= 1.104 x GENITAL + 1.328 x PUBIC HAIR + 5.997 x TESTES SIZE (mL).

Adolescent↗

PubMedDate not supplied

Adolescent blood pressure, anger expression and hostility: possible links with body fat.

An uncertain relation between health and angry/hostile behaviour exists in the literature on adolescents. With data from a pilot study, one possible reason for this is explored: health measures such as blood pressure as well as angry/hostile behaviours may change with, or depend upon physical maturity, body size and body fatness. The sample consists of 60 African-, Hispanic-, and Anglo-American adolescents (15 to 16 years of age) drawn from a public school in Houston, TX. Using resting diastolic blood pressure as a model, in a sex stratified analysis, the following conclusions were reached: Physical maturity in girls and body height in boys were related to ethnicity in the sample and were confounders of the blood pressure and anger relationship. In girls secretive anger ('anger-in') and hostility were associated with increased body fat; expressive anger ('anger-out') in boys is associated with increased conicity (central body fat distribution) (p < 0.01). These associations were independent of height and physical maturity. Hostility was not significantly related to diastolic blood pressure in boys after adjusting for height and conicity. 'Anger-in' was significantly and positively related to diastolic blood pressure in girls (p < 0.01). This relationship was strongly mediated by per cent body fat, because the association of 'anger-in' and blood pressure was no longer statistically significant when the model included body fat. The results suggest that measures of physical maturity and more refined measures of body fat and body fat distribution should be considered in studies attempting to link adolescent blood pressure with anger expression.

Adolescent↗

PubMedDate not supplied

Stress-induced alterations of blood pressure and 24 h ambulatory blood pressure in adolescents.

OBJECTIVE: To examine the extent to which ambulatory blood pressure was predicted by blood pressure levels exhibited during talking segments of a laboratory protocol and by resting blood pressures in male and female adolescents from three ethnic groups: African, European and Hispanic Americans. DESIGN: This was a laboratory-field study incorporating an experimental study of reactivity of blood pressure during a laboratory protocol and an observational study of 24h ambulatory blood pressure (ABP) monitoring. METHODS: Resting blood pressure, reactivity of blood pressure, 24h ABP, and activity, height, and maturation of a multi-ethnic sample of 373 male and female adolescents aged 11-16 years were measured. A mixed-effects model for repeated measures was the statistical approach, with systolic and diastolic blood pressures as separate, dependent variables. RESULTS: Percentiles of ABP by sex, ethnic group, and height are presented. High and mixed blood pressure reactors in the laboratory had higher levels of 24h ABP and higher levels of blood pressure load during the daytime. African Americans had higher ABP than did European and Hispanic Americans. CONCLUSIONS: Blood pressure measured during laboratory tasks that require talking might be useful as a screening device to identify adolescents with high blood pressures. Further study will be necessary in order to quantify the sensitivity of the laboratory protocol as an indicator of high blood pressure compared with casual measurement of blood pressures. If laboratory patterns of blood pressure could be used to predict which individuals have high levels of blood pressure during the course of daily activities, the laboratory protocol would be a useful screening tool, identifying high-risk individuals.

Adolescent↗

PubMedDate not supplied

Comparison of brachial and calf blood pressures in infants.

PURPOSE: To compare brachial and calf blood pressures in infants under one year of age using the same size blood pressure cuff. METHODOLOGY: A convenience sample of 79 infants ages 4-300 days was selected from the General Pediatric, Pediatric Special Care, and Pediatric Intensive Care units in an acute care hospital located in the southern United States. Difference between brachial and calf blood pressures were compared using a paired t-test and defining the range of difference for 95% of the sample. RESULTS: There was no statistically significant difference in brachial and calf blood pressure measurements when assessed by paired t-test. The range of difference for 95% of the sample merits further clinical attention. CONCLUSION: Calf blood pressure measurements can be assessed routinely on infants under one year of age but it is important to consistently compare calf pressures to calf pressures and brachial pressures to brachial pressures.

Age Factors↗