CO(2) rebreathing: an undergraduate laboratory to study the chemical control of breathing.

The Read CO2 rebreathing method (Read DJ. A clinical method for assessing the ventilatory response to carbon dioxide. Australas Ann Med 16: 20-32, 1967) provides a simple and reproducible approach for studying the chemical control of breathing. It has been widely used since the modifications made by Duffin and coworkers. Our use of a rebreathing laboratory to challenge undergraduate science students to investigate the control of breathing provided 8 yr of student-generated data for comparison with the literature. Students (age: 19-22 yr, Research Ethics Board approval) rebreathed from a bag containing 5% CO2 and 95% O2 (to suppress the peripheral chemoreflex to hypoxia). Rebreathing was performed, and ventilation measured, after hyperventilation to deplete tissue CO2 stores and enable the detection of the central chemoreflex threshold. We analyzed 43 data sets, of which 10 were rejected for technical reasons. The mean threshold and ventilatory sensitivity to CO2 were 43.3 ± 3.8 mmHg and 4.60 ± 3.04 l·min(-1)·mmHg(-1) (means ± SD), respectively. Threshold values were normally distributed, whereas sensitivity was skewed to the left. Both mean values agreed well with those in the literature. We conclude that the modified rebreathing protocol is a robust method for undergraduate investigation of the chemical control of breathing.

Equivalencies regarding the measurement and constructs of self-esteem and major life events in an Asian/Pacific islander sample.

Construct, scalar, and functional measurement equivalencies of the Rosenberg Self-Esteem Scale (RSES) and Major Life Events checklist (MLE) and the constructs assessed were investigated across groups differentiated on Hawaiian/part-Hawaiian and non-Hawaiian (e.g., Caucasian, Filipino, Hispanic, Japanese, and mixed/2 or more) ethnicity and gender. Initial results from maximum likelihood factoring with promax rotation showed that RSES negatively worded Item 5 loaded with the positively worded Items 1, 2, 4, 6, and 7 on 1 of 2 factors for Hawaiian/part-Hawaiian female participants. Similarly, negatively worded Item 8 and the same positively worded items comprised 1 of 2 factors for non-Hawaiian male participants. For the other 2 Ethnicity x Gender groups, factors were respectively comprised of the 5 positively and 5 negatively worded RSES items. Construct equivalence or simple (2-factor) structure underlying the RSES was indicated across the 4 groups after Items 5 and 8 were excluded from a subsequent factoring procedure. Simple structure showed that Factor 1 comprised the positively worded Items 1, 2, 4, 6, and 7, and the remaining negatively worded Items 3, 9, and 10 loaded on Factor 2. Scalar equivalence of the self-esteem and major life events measures was supported by the statistical nonsignificance of the Major Life Events x Ethnicity x Gender interaction effect in multiple regression models. The consistency in the absolute size and direction of the intercorrelations between overall self-esteem, self-esteem Factors 1 and 2, and major life events variables indicated the functional equivalence of respective measures and constructs assessed. Measurement equivalency findings concerning the RSES and MLE, the constructs measured, and their utility versus caution against their use in multiethnic studies were discussed.

Prediction of anxiety disorders using the state-trait anxiety inventory for multiethnic adolescents.

The purpose of this study was to determine the validity of the State-Trait Anxiety Inventory (STAI) in predicting DSM-III-R anxiety disorders based on the Diagnostic Interview Schedule for Children (DISC, Version 2.3) and using Asian/Pacific Islander adolescents. An overall prevalence rate of 9.19% for generalized anxiety disorder, overanxious disorder, or social phobia was consistent with past studies. As hypothesized, STAI negatively worded (i.e., Factor 2) items were better predictors than positively stated (i.e., Factor 1) items. The STAI State mean was a better predictor of concurrent DISC anxiety disorders as compared to STAI State Factors I or 2. In contrast, the STAI Trait Factor 2 (negatively worded) composite was the best predictor for nonconcurrent DISC anxiety disorders as compared to STAI Trait Factor 1 or the overall STAI Trait subscale. Satisfactory predictive-validity values were obtained when using the STAI State mean and Trait Factor 2 composite. Implications of these findings are discussed, including using the STAI as a screening measure for ethnically diverse adolescents.

Prediction of DISC substance abuse and dependency for ethnically diverse adolescents.

PURPOSE: This study examines the validity of selected items from the Substance Abuse Subtle Screening Inventory-Adolescent (SASSI-A) version in predicting Diagnostic Interview Schedule for Children (DISC version 2.3) Substance abuse and dependency (SA/D) for Native Hawaiian (i.e., indigenous people of the Hawaiian Islands) and non-Hawaiian adolescents (youth without any Native Hawaiian indigenous ancestry). METHODS: 542 students were randomly selected from the larger sample to participate in the DISC administration. Demographic information, SASSI-A scores, and DISC diagnoses were obtained for each student. Univariate and multiple logistic regressions were performed in the prediction of DISC SA/D. RESULTS: SASSI-A Factor 1, consisting of three items measuring substance use, was found to have the best utility, accounting for 18.1% of the variance, in predicting DISC SA/D. IMPLICATIONS: These results support selected SASSI-A items in screening for SA/D for Native Hawaiian and non-Hawaiian adolescents in Hawaii as compared to other community-based screening instruments for other populations.

Psychometric properties of the Hawaiian Culture Scale--Adolescent Version.

This article reports on the psychometric properties of a newly constructed Hawaiian Culture Scale--Adolescent Version. A total of 2,272 Native Hawaiian and 1,170 non-Hawaiian adolescents were administered this 50-item inventory that measures the source of learning the Hawaiian way of life, how much Hawaiian beliefs are valued and important to maintain, how much non-Hawaiian beliefs are valued, Hawaiian blood quantum, and specific cultural traditions (seven subscales = Lifestyles, Customs. Activities, Folklore, Causes-Locations, Causes-Access, and Language Proficiency). The results strongly supported the internal consistency and validity of the measures for both the Hawaiian and non-Hawaiian groups. On the basis of the demographic data, partial support was offered for cross-cultural theories of ethnic identity. More consistent support was found for multiculturalism in Hawai'i's adolescents. Further research is needed to link these measures with indicators of psychological adjustment (e.g., depression, anxiety, substance use).

Cultural identification and attempted suicide in Native Hawaiian adolescents.

OBJECTIVES: To determine rates of lifetime suicide attempts in a community sample of Native Hawaiian adolescents and determine the contribution of Hawaiian cultural affiliation, socioeconomic status, and psychiatric symptoms as risk factors for suicide. METHOD: High school students were surveyed in the state of Hawaii for lifetime suicide attempts, Hawaiian cultural affiliation, socioeconomic status, and symptoms of depression, substance abuse, aggression, and anxiety. Multiple logistic regressions were used on 3,094 subjects to develop prediction models for lifetime suicide attempts. RESULTS: Native Hawaiian adolescents had significantly higher rates of suicide attempts (12.9%) than other adolescents in Hawaii (9.6%). Hawaiian cultural affiliation rather than ethnicity was uniquely predictive of suicide attempts. Logistic regression indicated that depression, substance abuse, grade level, Hawaiian cultural affiliation, and main wage earner's education best predicted suicide attempts in Native Hawaiian adolescents, while depression, substance abuse, and aggression predicted suicide attempts in non-Hawaiians. CONCLUSIONS: Native Hawaiian adolescents have higher rates of attempted suicide than non-Hawaiian adolescents. Strong Hawaiian cultural affiliation rather than ethnicity is a risk factor for attempted suicide.

Psychometric properties of the state-trait anxiety inventory for Asian/Pacific-islander adolescents.

Anxiety disorders are said to be universal across all cultures and recent reviews have found relatively high prevalence rates across different countries. However, the experience and interpretation of anxiety are strongly influenced by cultural factors. Demonstrating cross-cultural equivalence of measures of anxiety is essential to assure that comparisons between cultures will result in meaningful interpretations. Despite the State-Trait Anxiety Inventory being the most researched of anxiety measures from a cross-cultural basis, there is a lack of empirical studies on the psychometric properties of the STAI with adolescent Asian/Pacific Islanders. The present study examined the STAI using a large sample of ethnically diverse high school students in Hawaii. In general, a four-factor model (State-Anxiety Absent, State-Anxiety Present, Trait-Anxiety Absent, and Trait-Anxiety Present) provided the best fit based on a series of confirmatory factor analyses. Indicators of internal consistency supported the reliability of the factors and subscales, and the inter-factor correlations reflected positively on the concurrent validity of the different STAI factor and subscale measures. This study suggested cautious use and interpretation of one particular item (Trait Item 14 = I try to avoid facing a crisis or difficulty ), and cautious application of the STAI to Filipino adolescents (particularly Filipino males). Domains for further research are discussed.

Prediction of major depression and dysthymia from CES-D scores among ethnic minority adolescents.

OBJECTIVE: The Native Hawaiian Mental Health Research Development Program is an epidemiological longitudinal study of adolescents residing in Hawaii. This article examines the utility of the Center for Epidemiologic Studies-Depression Scale (CES-D) for predicting DSM-III-R diagnoses of major depression (MD) and dysthymic disorder (DD) and investigates whether prediction differs by gender and ethnicity. METHOD: Diagnostic Interview Schedule for Children interviews were conducted with 556 adolescents randomly selected from among more than 7,000 students who had completed the CES-D. RESULTS: Six-month prevalence rates were as follows: MD = 8.5%, DD = 4.7%, either (MDDD) = 9.9%. Prevalence rates were significantly higher among females, but after CES-D scores were accounted for, gender no longer predicted depression in most analyses. When a cutoff score of 16 was used, classification accuracy was lower for Native Hawaiians than non-Hawaiians. However, after group differences in gender and grade level were accounted for, the predictive validity of the CES-D did not differ by ethnicity. CES-D factor 1 scores identified MD, DD, and MDDD about as well as the total score or all three factors together. CONCLUSIONS: These results support the validity of the CES-D for screening for depression among adolescents of Native Hawaiian and other minority backgrounds.

Psychosocial risk and protective influences in Hawaiian adolescent psychopathology.

A large community sample of adolescents of a Native Hawaiian (Asian/ Pacific Islander) minority group was studied along with a small comparison group of non-Hawaiians, for the relationship between psychopathology (as measured by standard symptom scales) and (a) perceived support from family and friends, and (b) discussing problems with others. Expected gender patterns for friend support but not for family support were found. The Hawaiian boys appeared atypical, reporting nearly equal family support as Hawaiian girls. Discussing problems with another person was correlated with lower anxiety and depression scores but not aggression and substance abuse scores. It is concluded that gender and cultural factors influence symptom prevalence and severity as well as the impact of psychosocial risk factors.