Biomedical subjects

Dedra Buchwald

Publications and source records attributed to Dedra Buchwald.

At least 19 recordsLinked to original sources

PubMed2006

Low-resolution electromagnetic brain tomography (LORETA) of monozygotic twins discordant for chronic fatigue syndrome.

BACKGROUND: Previous work using quantified EEG has suggested that brain activity in individuals with chronic fatigue syndrome (CFS) and normal persons differs. Our objective was to investigate if specific frequency band-pass regions and spatial locations are associated with CFS using low-resolution electromagnetic brain tomography (LORETA). METHODS: We conducted a co-twin control study of 17 pairs of monozygotic twins where 1 twin met criteria for CFS and the co-twin was healthy. Twins underwent an extensive battery of tests including a structured psychiatric interview and a quantified EEG. Eyes closed EEG frequency-domain analysis was computed and the entire brain volume was compared of the CFS and healthy twins using a multiple comparison procedure. RESULTS: Compared with their healthy co-twins, twins with CFS differed in current source density. The CFS twins had higher delta in the left uncus and parahippocampal gyrus and higher theta in the cingulate gyrus and right superior frontal gyrus. CONCLUSIONS: These findings suggest that neurophysiological activity in specific areas of the brain may differentiate individuals with CFS from those in good health. The study corroborates that slowing of the deeper structures of the limbic system is associated with affect. It also supports the neurobiological model that the right forebrain is associated with sympathetic activity and the left forebrain with the effective management of energy. These preliminary findings await replication.

Brain↗

PubMed2006

A case control study of premorbid and currently reported physical activity levels in chronic fatigue syndrome.

BACKGROUND: Patients with chronic fatigue syndrome typically report high levels of physical activity before becoming ill. Few studies have examined premorbid and current activity levels in chronically fatigued patients. METHODS: In a case-control study, 33 patients with chronic, unexplained, disabling fatigue attending a university-based clinic specializing in fatigue were compared to 33 healthy, age- and sex-matched controls. Patients rated their activity levels before their illness and currently, using scales designed for this purpose. Controls reported their level of activity of 2 years previously and currently. Chi-square analyses, Student's t tests, and Wilcoxon signed rank tests were used in pair matched analyses. RESULTS: Compared to healthy controls, patients with chronic, unexplained fatigue rated themselves as more active before their illness (p < or = 0.001) and less active currently (p < or = 0.001). The patients also reported they currently stood or walked less than the controls (median [inter-quartile range] = 4 2345 versus 9 [7.5-12] hours, p < or = 0.001), and spent more time reclining (median [inter-quartile range] = 12 10111213141516 versus 8 [8-9.5] hours, p < or = 0.001). These differences remained significant for the subset of patients who met strict criteria for chronic fatigue syndrome or fibromyalgia. CONCLUSION: Patients with chronic, unexplained, disabling fatigue reported being more active before becoming ill than healthy controls. This finding could be explained by greater premorbid activity levels that could predispose to illness, or by an overestimation of previous activity. Either possibility could influence patients' perceptions of their current activity levels and their judgments of recovery. Perceived activity should be addressed as part of management of the illness.

Activities of Daily Living↗

PubMed2006

Mortality in a cohort of chronically fatigued patients.

BACKGROUND: Comprehensive studies of mortality among patients with chronic fatigue (CF) and chronic fatigue syndrome (CFS) have not been published, but several sources suggest that CFS is associated with an elevated risk for suicide. METHOD: Data on 1201 chronically fatigued patients followed in a university-affiliated tertiary-care clinic for up to 14 years were submitted to the Center for Disease Control and Prevention (CDC) National Death Index (NDI) to evaluate all-cause and suicide-caused death rates against standardized mortality rates (SMRs). We used Life Table Analysis to examine the influence of sex and diagnoses of CFS and depression. RESULTS: All-cause mortality in chronically fatigued patients was no higher than expected, but suicide-caused death rates were more than eight times higher than in the US general population. The significant elevation in the SMR of suicide was restricted to those who did not meet criteria for CFS [SMR(CF)=14.2, 95% confidence interval (CI) 5.7-29.3 versus SMR(CFS)=3.6, 95% CI 0.4-12.9]. Among chronically fatigued patients who did not meet CFS criteria, those with a lifetime history of major depression (MD) had higher suicide-caused death rates than among their non-depressed counterparts (SMR(MD)=19.1, 95% CI 7.0-41.5 versus SMR(NMD)=5.6, 95% CI 0.1-31.4), although the difference was not significant. CONCLUSIONS: CFS does not appear to be associated with increased all-cause mortality or suicide rates. Clinicians, however, should carefully evaluate patients with CF for depression and suicidality.

Cohort Studies↗

PubMed2006

Genetic and environmental influences on insomnia, daytime sleepiness, and obesity in twins.

STUDY OBJECTIVES: To better understand the relationships of insomnia, sleepiness, and obesity. DESIGN: Classic twin study. SETTING: A community-based twin registry in Washington State. PATIENTS OR PARTICIPANTS: One thousand forty-two monozygotic and 828 dizygotic twin pairs participating in the University of Washington Twin Registry. INTERVENTIONS: N/A. MEASUREMENTS AND RESULTS: Twins were, on average, 32 years old; 61% were women, and 19.5% were obese, defined as a body mass index > or = 28. Insomnia and sleepiness were endorsed by 19.3% and 3.7% of twins, respectively. Twin correlations were higher in monozygotic than dizygotic twins for insomnia (0.47 versus 0.15), sleepiness (0.37 versus 0.14), and obesity (0.82 versus 0.46). Heritability estimates were 57% for insomnia (p < .001; 95% confidence interval 47-63), 38% for sleepiness (p < .01; 95% confidence interval 16-46), and 73% for obesity (p < .001; 95% confidence interval 49-87). Multivariate genetic model fitting revealed that common additive genetic effects comprised 12.8% of the phenotypic correlation between insomnia and sleepiness (p < .01) and 10% of the phenotypic correlation between insomnia and obesity (p < .01). The phenotypic correlation between sleepiness and obesity was not due to common additive genetic effects. CONCLUSIONS: Insomnia, sleepiness, and obesity are under strong genetic influence. Common genetic effects were observed between insomnia and both sleepiness and obesity, suggesting shared genetic contributions to these phenomena.

Adolescent↗

PubMed2006

The relationship between patterns of alcohol use and mental and physical health disorders in two American Indian populations.

AIMS: First, define alcohol use categories among two reservation-based American Indian (AI) populations based on the relationship between alcohol consumption and dependence. Secondly, examine associations between the alcohol use categories and other indicators of health status. DESIGN, PARTICIPANTS AND MEASUREMENTS: Epidemiological data on 1287 AIs aged 18-57 years who consumed alcohol during the past year. CHAID tree analysis, a hierarchical partitioning method, was used to analyze alcohol quantity (highest number of drinks consumed during 1 day) and frequency (number of days drank during the past month) data to define quantity-frequency categories distinguished by differing rates of alcohol dependence. Multivariate analyses assessed relationships between the alcohol use categories thus identified and a number of health outcomes. FINDINGS: People who reported drinking 12 or more drinks during 1 day and more than 4 days a month had the highest prevalence of alcohol dependence. Among the males who drank > 18 drinks the prevalence was 42.12% and among females who drank 12 or more drinks, 44.58%. The prevalence among males who drank > 18 drinks yet drank less frequently was also high (24.06%). Although findings differed by gender, drinkers in the highest risk category for alcohol dependence were most likely to report drug use disorders, mood/anxiety disorders, alcohol-related physical disorders and lower quality of life. CONCLUSIONS: The quantity thresholds defined to identify AIs at highest risk for alcohol dependence in this study differed by gender and were higher than typically reported for non-AIs. They are consistent with previous findings regarding the pattern of high-quantity, low-frequency alcohol consumption among AIs residing on reservations.

Adolescent↗

PubMed2006

Attitudes of urban American Indians and Alaska Natives regarding participation in research.

OBJECTIVE: To determine what factors influence participation in health research among American Indians and Alaska Natives. METHODS: Using vignettes that described 3 types of research studies (a behavioral intervention trial, a genetic association study, and a pharmacotherapy trial), we surveyed 319 patients and 101 staff from an urban Indian health care facility to ascertain how study design, institutional sponsorship, community involvement, human subjects' issues, and subject matter influence participation. RESULTS: Overall response rates were 93% for patients and 75% for staff. Hypothetical participation was highest for the genetic study (patients=64%; staff=48%), followed by the behavioral intervention (patients=46%; staff=42%), and the pharmacotherapy trial (patients=32%; staff=23%). The odds of participation (odds ratio [OR]) were generally increased among patients and staff when the study was conducted by health care providers (OR=1.3 to 2.9) and addressed serious health problems (OR=1.2 to 7.2), but were decreased if the federal government led the study (OR=0.3 to 0.5), confidentiality might be broken (OR=0.1 to 0.3), and compensation was not provided (OR=0.5 to 0.7). CONCLUSION: Close attention to study type, institutional sponsorship, community involvement, potential risks and benefits, and topic are essential to conceptualizing, designing, and implementing successful health research with American Indian and Alaska Native populations.

Adult↗

PubMed2006

Comorbidity of alcohol abuse and dependence with medical conditions in 2 American Indian reservation communities.

BACKGROUND: The objective was to examine the association of self-reported Diagnostic and Statistical Manual-IV edition alcohol abuse and dependence with medical conditions among American Indians (AIs). METHODS: We analyzed data previously collected in a large epidemiological study of members of 2 culturally distinct AI tribes from the Southwest (SW; n = 1,446) and the Northern Plains (NP; n = 1,638) living on or near their reservations. Associations of combined self-reported alcohol abuse and alcohol dependence with 19 medical conditions were examined through multinomial logistic regression. RESULTS: Medical conditions that had significant relationships with alcohol abuse/dependence were sprains and strains [odds ratio (OR) 2.04, p < 0.001], hearing and vision problems (OR 2.05, p < 0.001), kidney and bladder problems (OR 1.55, p < 0.01), head injuries (OR 2.20, p < 0.001), pneumonia/tuberculosis (OR 1.49, p < 0.01), dental problems (OR 1.89, p < 0.001), and liver problems/pancreatitis (OR 2.18, p < 0.001). The total count of medical conditions was also significantly related to alcohol abuse/dependence, with a higher count being associated with the outcome (OR 1.17, p < 0.001). CONCLUSIONS: In this community-based study of rural AIs, diverse medical conditions were associated with alcohol abuse and dependence. Further research should examine, and confirm, the nature, extent, and tribal variation of the medical consequences of alcohol abuse and dependence in these unique populations.

Adolescent↗

PubMed2006

Using mail to reach patients seen at an urban health care facility.

Urban American Indians/Alaska Natives (AI/ANs) are highly mobile, and little is known about ways to include them in research or clinical activities. We evaluated postal mailings as a means of reaching patients seen at an urban Indian health care facility (60% of whom were AI/AN) and identified factors associated with receipt of mail. As part of a clinical trial, a Native art calendar was sent via first class mail to 5,633 clients seen at the urban Indian clinic during the prior two years. A multi-step address verification process was conducted, including telephone contacts, Web searches, and in-person visits. Logistic regressions examined the association of client characteristics with accurate addresses. Based on initial mailings and in-person location efforts, we estimated that only 61% of clients actually received the calendars. The multi-step address verification process was significantly less likely to identify working addresses for clients who were AI/AN and clients who were seen more than 3 months before the study. Reaching urban AI/ANs for research activities and health care is difficult. Innovative strategies are needed to locate this highly mobile and understudied population.

Adolescent↗

PubMed2006

Perceived discrimination in health care among American Indians/Alaska natives.

OBJECTIVES: We compared the prevalence of, and reasons for, perceived discrimination in health care among American Indian/Alaska Natives (AI/ANs) and persons of AI/AN + White heritage to African Americans, Asian Americans, and Whites. DESIGN: Data on perceived discrimination were collected by the 2001 California Health Interview Survey (CHIS). We used chi-square tests to evaluate the prevalence of perceived discrimination and the reasons for perceived discrimination across racial groups. SETTING: The 2001 CHIS, a telephone survey, one of the largest cross-sectional surveys ever conducted in the United States. PARTICIPANTS: Participants in this analysis were adults > or = 18 years of age, interviewed from 55,000 households that took part in the survey. INTERVENTIONS: Participants in the 2001 CHIS were asked "Thinking of your experiences with receiving health care in the past 12 months, have you felt you were discriminated against for any reason?" Respondents who endorsed this item were asked about possible reasons for the discrimination. MAIN OUTCOME MEASURES: 1) Does the prevalence of perceived discrimination in health care differ between AI/ANs, AI/AN + Whites, African Americans, Asian Americans, and Whites? and 2) Do the reasons for perceived discrimination in health care vary by race or ethnicity? RESULTS: Discrimination was perceived by 7.1% of the AI/AN alone group, 8.8% of AI/AN + White respondents, 5.6% of African Americans, 4.3% of Whites, and 2.6% of Asian Americans. After adjusting for covariates, the odds of perceived discrimination were different for AI/AN + White (odds ratio [OR] =2.0, 95% confidence interval [CI] 1.5-2.5) and Asian American (OR = .5, 95% CI .4-.7) when compared to Whites. CONCLUSIONS: AI/ANs, and especially those who identify as AI/AN + White, were the most likely among racial groups to report discrimination in health care.

Adolescent↗

PubMed2005

Cultural identities and perceptions of health among health care providers and older American Indians.

BACKGROUND: Differences in provider-patient health perceptions have been associated with poor patient outcomes, but little is known about how patients' cultural identities may be related to discordant perceptions. OBJECTIVE: To examine whether health care providers and American-Indian patients disagreed on patient health status ratings, and how differences related to these patients' strength of affiliation with American-Indian and white-American cultural identities. DESIGN: Survey of patients and providers following primary care office visits. PARTICIPANTS: One hundred and fifteen patients > or =50 years and 7 health care providers at a Cherokee Nation clinic. All patients were of American-Indian race, but varied in strength of affiliation with separate measures of American-Indian and white-American cultural identities. MEASUREMENTS: Self-reported sociodemographic and cultural characteristics, and a 5-point rating of patient's health completed by both patients and providers. Fixed-effects regression modeling examined the relationships of patients' cultural identities with differences in provider-patient health rating. RESULTS: In 40% of medical visits, providers and patients rated health differently, with providers typically judging patients healthier than patients' self-rating. Provider-patient differences were greater for patients affiliating weakly with white cultural identity than for those affiliating strongly (adjusted mean difference=0.70 vs 0.12, P=.01). Differences in ratings were not associated with the separate measure of affiliation with American-Indian identity. CONCLUSIONS: American-Indian patients, especially those who affiliate weakly with white-American cultural identity, often perceive health status differently from their providers. Future research should explore sources of discordant perceptions.

Attitude of Health Personnel↗

PubMed2005

Genetic pleiotropy between asthma and obesity in a community-based sample of twins.

BACKGROUND: Asthma and obesity are common conditions that are strongly associated. This association might be due to shared genetic or environmental causes. OBJECTIVE: We sought to determine whether a shared genetic cause is responsible for the association between asthma and obesity and to estimate the magnitude of shared genetic cause. METHODS: The analyses were performed with 1001 monozygotic and 383 dizygotic same-sex twin pairs within the University of Washington Twin Registry. The presence of asthma was determined by self-report of a physician diagnosis of asthma, and body mass index (BMI) was calculated by using self-reported height and weight. Obesity was defined as a BMI of 30 or greater. The association between asthma and BMI was assessed by means of mixed-effects ordinal regression. Twin correlations examined the association of asthma and obesity. Univariate and bivariate structural equation models estimated the components of variance attributable to genetic and environmental effects. RESULTS: A strong association between asthma and BMI was identified in the sample population (P < .001). Substantial heritability was detected for asthma (53%) and obesity (77%), which is indicative of additive genetic influences on each disorder. The best-fitting model of shared components of variance indicated that 8% of the genetic component of obesity is shared with asthma. CONCLUSION: The covariation between obesity and asthma is predominantly caused by shared genetic risk factors for both conditions.

Adult↗

PubMed2005

A randomized clinical trial of acupuncture compared with sham acupuncture in fibromyalgia.

BACKGROUND: Fibromyalgia is a common chronic pain condition for which patients frequently use acupuncture. OBJECTIVE: To determine whether acupuncture relieves pain in fibromyalgia. DESIGN: Randomized, sham-controlled trial in which participants, data collection staff, and data analysts were blinded to treatment group. SETTING: Private acupuncture offices in the greater Seattle, Washington, metropolitan area. PATIENTS: 100 adults with fibromyalgia. INTERVENTION: Twice-weekly treatment for 12 weeks with an acupuncture program that was specifically designed to treat fibromyalgia, or 1 of 3 sham acupuncture treatments: acupuncture for an unrelated condition, needle insertion at nonacupoint locations, or noninsertive simulated acupuncture. MEASUREMENTS: The primary outcome was subjective pain as measured by a 10-cm visual analogue scale ranging from 0 (no pain) to 10 (worst pain ever). Measurements were obtained at baseline; 1, 4, 8, and 12 weeks of treatment; and 3 and 6 months after completion of treatment. Participant blinding and adverse effects were ascertained by self-report. The primary outcomes were evaluated by pooling the 3 sham-control groups and comparing them with the group that received acupuncture to treat fibromyalgia. RESULTS: The mean subjective pain rating among patients who received acupuncture for fibromyalgia did not differ from that in the pooled sham acupuncture group (mean between-group difference, 0.5 cm [95% CI, -0.3 cm to 1.2 cm]). Participant blinding was adequate throughout the trial, and no serious adverse effects were noted. LIMITATIONS: A prescription of acupuncture at fixed points may differ from acupuncture administered in clinical settings, in which therapy is individualized and often combined with herbal supplementation and other adjunctive measures. A usual-care comparison group was not studied. CONCLUSION: Acupuncture was no better than sham acupuncture at relieving pain in fibromyalgia.

Acupuncture Therapy↗

PubMed2005

Surgical morbidity and mortality among American Indian and Alaska Native veterans: a comparative analysis.

BACKGROUND: Few studies have examined surgical risk factors and outcomes in American Indians and Alaska Natives (AI/ANs). My colleagues and I sought to determine if prevalence of preoperative risk factors for morbidity and mortality differed between male AI/AN and Caucasian surgical patients, and to determine if AI/ANs had an increased risk of surgical morbidity or mortality. STUDY DESIGN: We obtained data from the Veterans Affairs National Surgical Quality Improvement Program on major, noncardiac, surgical procedures performed between 1991 and 2002 for all AI/AN men (n = 2,155) and a random sample of Caucasian men (n = 2,264), matched by facility. Chi-square and t-test analyses were used to assess differences in preoperative risk factors between the two groups. Logistic regression was used to determine whether AI/AN race was independently associated with 30-day morbidity (defined as 1 or more of 21 postoperative complications) or 30-day all cause mortality after adjustment for major risk factors. RESULTS: Prevalence of major preoperative risk factors for morbidity and mortality often differed between the groups. Compared with Caucasians, AI/AN race did not predict morbidity (adjusted odds ratio, 0.92; 95% CI, 0.75-1.13), but AI/ANs were at higher risk for 30-day all cause postoperative mortality (adjusted odds ratio, 1.56; 95% CI, 1.04-2.35). CONCLUSIONS: Our results add postoperative mortality to health disparities experienced by AI/ANs. Future research should be conducted to identify other factors that contribute to this disparity.

Aged↗

PubMed2005

A longitudinal study of physical activity and body mass index among persons with unexplained chronic fatigue.

OBJECTIVE AND METHODS: A cohort of 100 patients with unexplained chronic fatigue (CF) was assessed longitudinally for 1.5 years to determine if physical activity (kcal expended), exercise capacity (VO(2)max), perceived exertion, and body mass index (BMI) changed over time and were associated with changes in CF-related clinical status. RESULTS: BMI increased significantly over time but did not predict changes in clinical status. Increasing energy expenditure was associated with increasing vitality and decreasing CF symptom severity over time, and decreasing perceived exertion was associated with increasing physical functioning. However, increasing perceived exertion was also associated with increasing CF symptoms. CONCLUSIONS: These data do not support models that posit associations between CF and deconditioning.

Adult↗

PubMed2005

The prevalence of self-reported chronic fatigue in a U.S. twin registry.

OBJECTIVE: To investigate the prevalence and correlates of various definitions of self-reported lifetime fatiguing illness in a U.S. twin registry. METHODS: Data from 4591 female and male twins from the population-based Mid-Atlantic Twin Registry were available for this study. Variables representing different definitions of lifetime fatiguing illness and personal characteristics were obtained through questionnaires. Odds ratios and 95% confidence intervals were calculated as measures of association between fatigue and gender. Kaplan-Meier curves were produced to examine the age at onset for lifetime fatiguing illnesses. RESULTS: Prevalences for different definitions of self-reported lifetime fatigue ranged from 36.7% for any fatigue to 2.7% for chronic fatigue syndrome-like illness. Females were two to three times more likely to report fatigue than males. Gender differences increased as fatigue definitions grew more restrictive. Ages at onset of chronic fatiguing illness were significantly earlier and the number of ancillary symptoms was greater for females than males. People with lifetime fatigue had significantly more compromised functional status than people without lifetime fatigue. CONCLUSION: The prevalence of self-reported lifetime fatiguing illness varied widely depending upon how it was defined. Given the debilitating consequences of fatiguing illnesses, the reasons for the female predominance and the earlier onset in women should receive increased research priority.

Adult↗

PubMed2005

The relationship between post-traumatic stress disorder, depression and cardiovascular disease in an American Indian tribe.

BACKGROUND: Empirical findings suggest that psychiatric illness is associated with cardiovascular disease (CVD). The purpose of this study was to compare the strength of the association of lifetime post-traumatic stress disorder (PTSD) and lifetime major depression on CVD among Northern Plains American Indians. METHOD: A total of 1414 participants aged 18-57 years completed a structured interview that assessed psychiatric diagnoses, alcohol abuse/dependence, self-reported CVD, and traditional CVD risk factors including age, sex, education, diabetes, high blood pressure, and smoking. Logistic regression analyses compared the odds ratios of CVD in participants with and without diagnosed PTSD or major depression. RESULTS: The rates of lifetime PTSD and major depression were 15% and 8% respectively. CVD was more commonly reported by participants with PTSD than by those without PTSD (12% v. 5%, p<or=0.01). Likewise, more participants with major depression reported CVD than did their non-depressed counterparts (14% v. 6%, p<or=0.05). PTSD was significantly associated with CVD even after controlling for traditional CVD risk factors and major depression (odds ratio 2.0, confidence interval 1.1-3.8). In contrast, the association of major depression with CVD was not significant after accounting for both traditional risk factors and PTSD. CONCLUSIONS: Rates of PTSD are high in American Indian communities. Rising CVD rates in this population may be better understood if PTSD is considered along with other traditional risk factors. Future research should examine the association and mechanisms of PTSD and CVD prospectively. Such data could lead to more effective CVD prevention efforts for American Indians.

Adolescent↗

PubMed2005

Characteristics associated with reservation travel among urban Native American outpatients.

The objectives of this study were to ascertain the extent of, and health-related characteristics associated with, travel to reservations in a low-income, urban American Indian and Alaska Native (AI/AN) population. We surveyed more than 500 AI/AN adults at a primary care clinic. Measures included time spent visiting a reservation during the past year, and sociodemographic, cultural, and clinical characteristics. More than half (52%) of the patients had not traveled, 34% had traveled up to 30 days, and 14% had spent more than 30 days traveling to reservations. Multivariate ordinal regression revealed that a strong Native American cultural identification, presence of lung disease, absence of thyroid and mental problems, and greater dissatisfaction with care were independently associated with more travel to reservations (p<or=0.05). This research begins to augment the paucity of information on such travel and its relationship to health status and use of health services among urban AI/ANs.

Adult↗

PubMed2004

Subjective and objective sleepiness in monozygotic twins discordant for chronic fatigue syndrome.

STUDY OBJECTIVE: To examine the association of chronic fatigue syndrome (CFS) with measures of objective and subjective sleepiness. DESIGN: Monozygotic co-twin control study. SETTING: Academic medical center. PATIENTS AND PARTICIPANTS: Twenty monozygotic twin pairs discordant for CFS. INTERVENTIONS: N/A. MEASUREMENTS AND RESULTS: All twins completed an Epworth Sleepiness Scale (ESS), 4 Stanford Sleepiness Scales (SSS), and underwent a standard 4-nap multiple sleep latency test. We compared the ESS scores, average SSS scores, and average sleep latency in CFS and healthy twins. The CFS twins reported more sleepiness as measured by mean scores on the ESS (10.9 vs 8.2; 95% confidence interval [CI] = 0.3-5.5; P = .03) and the SSS (3.4 versus 2.1; 95% CI = 0.7-1.9; P < .001). The mean sleep latency on the Multiple Sleep Latency Test was not significantly different between the CFS and healthy twins (8.9 vs 10.0 minutes; 95% CI -4.4-1.7; P = .33). Mean SSS scores increased among the CFS twins and decreased among healthy twins from nap 1 to nap 4 (P < .001). The individual ESS scores and mean sleep latencies on the Multiple Sleep Latency Test were negatively correlated for all the twins (Pearson's r = - 0.40; P = .01), with a slightly stronger association among the healthy twins (Pearson's r = -0.42, P = .07) than the CFS twins (Pearson's r = -0.36, P = .15). CONCLUSIONS: CFS twins reported significantly more subjective sleepiness than their healthy co-twins despite similar nonpathologic mean sleep latencies on the Multiple Sleep Latency Test. Patients with CFS may mistake their chronic disabling fatigue for sleepiness.

Adult↗