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PubMed2004

Factors affecting the spread and duration of epidural anesthesia with ropivacaine.

BACKGROUND: Epidural anesthesia has an unpredictable extent and duration. Differences in the surface area of the lumbosacral dura, epidural fat volume, and epidural venous plexus velocity might explain the variability in the extent and duration of epidural anesthesia with ropivacaine. METHODS: Twenty-six healthy patients, aged 18-45 y, undergoing peripheral orthopedic surgery were enrolled. Dural surface area and posterior epidural fat volume were calculated from low thoracic, lumbar, and sacral axial magnetic resonance images obtained at 8-mm increments. Epidural venous plexus velocity at the L3-L4 disk level was derived from phase-contrast magnetic resonance images. The patients received 100 mg ropivacaine (1.0%) epidurally. The spread and duration of sensory anesthesia was assessed by pinprick, and that of motor block was assessed using a modified Bromage scale. Statistical correlation coefficients (rho) between magnetic resonance imaging and epidural anesthesia measurements were assessed by Spearman rank correlation. Stepwise multiple linear regression models were used to select important predictors of measures of epidural anesthesia. RESULTS: Dural surface area correlated with peak sensory block level (rho= -0.73, P = 0.0003) and onset time of caudal and cephalad block (rho = 0.62, P = 0.002; rho = -0.63, P = 0.002). Fat volume correlated with the regression to L5-S3 (rho = -0.44.44 to -0.54, P = 0.029 to 0.007). Epidural venous plexus velocity was significantly correlated with the regression to L3 (rho = -0.42, P = 0.038) and L4 (rho = -0.48, P = 0.017). Multiple regression analysis revealed that dural surface area was a significant predictive variable for the peak sensory block level (R = 0.61, P < 0.0001). CONCLUSIONS: These findings indicate that dural surface area influences the spread of epidural anesthesia with ropivacaine and posterior fat volume influences the duration of epidural anesthesia in healthy patients within a narrow age range. Epidural venous plexus velocity might also influence the duration of epidural anesthesia with ropivacaine.

Adipose Tissue↗

PubMed2006

Left atrial size and risk of major cardiovascular events during antihypertensive treatment: losartan intervention for endpoint reduction in hypertension trial.

The influence of left atrial size on cardiovascular events during antihypertensive treatment has not been reported previously from a long-term, prospective, randomized hypertension treatment trial. We recorded left atrial diameter by annual echocardiography and cardiovascular events in 881 hypertensive patients (41% women) with electrocardiographic left ventricular hypertrophy aged 55 to 80 (mean: 66) years during a mean of 4.8 years of randomized losartan- or atenolol-based treatment in the Losartan Intervention for Endpoint Reduction in Hypertension Study. During follow-up, a total of 88 primary end points (combined cardiovascular death, myocardial infarction, or stroke) occurred. In Cox regression, baseline left atrial diameter/height predicted incidence of cardiovascular events (hazard ratio: 1.98 per cm/m [95% CI: 1.02 to 3.83 per cm/m]; P=0.042) adjusted for significant effects of Framingham risk score and history of atrial fibrillation. Greater left atrial diameter reduction during follow-up was associated with greater reduction in left ventricular hypertrophy, absence of new-onset atrial fibrillation or mitral regurgitation during follow-up, and losartan-based treatment (B=-0.13+/-0.03 cm/m; P<0.001) in multiple linear regression, adjusting for baseline left atrial diameter/height. However, in time-varying Cox regression analysis, left atrial diameter reduction was not independent of left ventricular hypertrophy regression in predicting cardiovascular events during follow-up. In conclusion, left atrial diameter/height predicts risk of cardiovascular events independent of other clinical risk factors in hypertensive patients with left ventricular hypertrophy and may be useful in pretreatment clinical assessment of cardiovascular risk in these patients.

Aged↗

PubMedDate not supplied

Effects of 3-month treatment with the antioxidant alpha-lipoic acid in diabetic peripheral neuropathy.

Alpha lipoic acid is a natural antioxidant that has been suggested to improve symptoms of diabetic neuropathy. To assess these potential benefits, a cohort of 26 type 2 diabetic patients with symptomatic peripheral neuropathy (stage 2) received a daily dose of 600 mg alpha-lipoic acid, and were followed for a 3 month-period. No dropout was noted. At the end of the follow-up period, in 20 subjects (76.9%) there was a 1-stage regression of somatic neuropathy (from symptomatic to asymptomatic neuropathy, and in 5 patients (19.2%) no signs of neuropathy were found. The nerve conduction velocity of motor fibers improved from 36.8 (95% Confidence Interval CI = 30.9-42.7) meters/second to 41.3 (95% CI = 39.5-43.0) meters/second (p = 0.049, paired t test). Mean blood glucose measured was significantly lower at 3 months than at baseline [197.9 (95% CI = 170.1-225.7) versus 162.2 (95% CI = 146.1-178.2 mg/dl, p = 0.02, paired t test)]. In a multiple linear regression model with age. sex, body mass index, diabetes duration and the difference between blood glucose values at 3 months and at baseline as explanatory variables, the increment in nerve conduction velocity was not accounted for by the improved glycemic control. Women, thinner and younger patients tended to benefit more from the treatment in terms of nervous conduction velocity improvement. In conclusion, alpha-lipoic acid seems to be efficient and safe in the treatment of diabetic peripheral neuropathy, improving both clinical manifestations and nerve conduction velocity. Placebo controlled clinical trials are needed to further define the role of this new medication in the treatment of diabetic neuropathies.

Antioxidants↗

PubMed1993

Women and AIDS: social determinants of sex-related activities.

Female sexual partners of injection drug users are at risk for AIDS because of their association with street drug cultures and all their concomitant risks, including their own non-injecting drug use. This study examines a model of the social determinants of HIV-associated sexual risk behaviors. Multiple linear regression analysis was used to analyze the data for 207 female sexual partners who had never injected drugs. The findings show that crack cocaine use is the strongest contributor to the model, which explains fourteen percent of the variance of sexual risk behavior. The findings suggest that the risks associated with sexual practices are much greater for crack cocaine users than among non users of crack.

Acquired Immunodeficiency Syndrome↗

PubMed1987

Value of nutritional parameters in the prediction of postoperative complications in elective gastrointestinal surgery.

The following nutritional parameters were assessed in 117 patients before major gastrointestinal surgery: percentage recent weight loss: percentage ideal body weight; tricipital skinfold; arm muscular area; grip strength dynamometry; serum albumin (ALB); serum transferrin (TFN); delayed hypersensitivity skin tests (DH); total lymphocyte count; prognostic nutritional index (PNI) and clinical assessment of malnutrition. Comparing the results in patients without complications (n = 99) with those in patients with complications (n = 18) and the results in patients who survived (n = 109) with those who died (n = 8), we found that only ALB, DH, TFN and PNI showed significant differences in both comparisons. Correlations of complications with combined parameters was made by multiple linear regression analysis; a modified PNI (mPNI), including these three single variables, has emerged. Considering its risk values, the nutritional parameters showed the following sensitivity and specificity, respectively: ALB less than 3.2 g/dl (72 and 71 per cent), anergy (67 and 64 per cent), TFN less than 205 mg/dl (67 and 55 per cent) and mPNI less than 20 (72 and 70 per cent). Using Bayes' theorems, ALB, DH and calculated indices showed the same predictive capacity and we conclude that single or multiple association of nutritional parameters have no additive effect. To predict complications of nutritional origin it seems only necessary to consider ALB, taking into account the type of operation and the normal duration of postoperative hospital stay without oral intake.

Adult↗

PubMed2005

Impact of nosocomial infection on cost of illness and length of stay in intensive care units.

OBJECTIVE: Economic evaluation has become increasingly important in healthcare and infection control. This study evaluated the impact of nosocomial infections on cost of illness and length of stay (LOS) in intensive care units (ICUs). DESIGN: A retrospective cohort study. SETTING: Medical, surgical, and mixed medical and surgical ICUs in a tertiary-care referral medical center. PATIENTS: Patients admitted to adult ICUs between October 2001 and June 2002 were eligible for the study. METHODS: Estimates of the cost and LOS for patients who acquired a nosocomial infection were computed using a stratified analysis and regression approach. RESULTS: During the study period, 778 patients were admitted to the ICUs. Total costs for patients with and without nosocomial infections (median cost, 10,354 dollars and 3985 dollars, respectively) were significantly different (P < .05). The costs stratified by infection site (median differences from 4687 dollars to 7365 dollars) and primary diagnosis (median differences from 5585 dollars to 16,507 dollars) were also significantly different (P < .05) except for surgical-site infection. After covariates were adjusted for in the multiple linear regression, nosocomial infection increased the total costs by 3306 dollars per patient and increased the LOS by 18.2 days per patient (P < .001). Each additional day spent in the ICU increased the cost per patient by 353 dollars (P < .001). CONCLUSIONS: Nosocomial infections are associated with increased cost of illness and LOS. Prevention of nosocomial infections should reduce direct costs and decrease the LOS.

APACHE↗

PubMed2003

Predicting effective continuous positive airway pressure in Taiwanese patients with obstructive sleep apnea syndrome.

BACKGROUND AND PURPOSE: Race/ethnicity plays an important role in determining body size and the severity of obstructive sleep apnea syndrome (OSAS), perhaps affecting the lowest effective continuous positive airway pressure (CPAP) [P(eff)] required to abolish sleep apneas. This study aimed to determine P(eff), using an optimal regression model to facilitate the titration of CPAP in Taiwanese people and to compare the findings of a regression model to the previously reported models developed in Caucasian populations. METHODS: 121 patients with moderate to severe OSAS were studied. All were titrated for nasal CPAP at a university hospital. The patients underwent separate polysomnographic studies to diagnose OSAS and to determine the P(eff) for home use. Seven polysomnographic variables were included in the analysis: apnea/hypopnea index (AHI), desaturation index (DI), desaturation duration, mean oxyhemoglobin saturation (S(P)O(2)), mean desaturation, nadir S(P)O(2), and snore index. Multiple linear regression was used to model the effects of anthropometric and polysomnographic variables on P(eff). A data-splitting cross-validation study and model fit criteria were used to select the predictors and assess the model performance. RESULTS: Most of the subjects were obese men who suffered severe OSAS with significant oxyhemoglobin desaturation and daytime sleepiness, and who required 8 cm H(2)O of CPAP. Age, body mass index (BMI), neck circumference (NC), AHI, DI, mean S(P)O(2), and daytime somnolence score were significantly associated with P(eff). The final prediction model (n = 121) was estimated as P(eff) = 0.52 + 0.174 x BMI + 0.042 x AHI, while the previously reported equation uses BMI, NC, and AHI. The prediction equation was more accurate in predicting P(eff) in this Taiwanese population as compared to the previously reported equations designed from a Caucasian sample. CONCLUSIONS: Obesity and severity of sleep apnea are the 2 most important predictors of CPAP setting effectively abolishing the apneas. After inclusion of BMI and AHI in the model, other variables (such as NC) do not significantly improve the prediction of P(eff), suggesting that ethic differences may play a role in predicting P(eff).

Adult↗

PubMed2006

[Associations between carotid intima-media thickness, plaque and cardiovascular risk factors].

OBJECTIVES: This study was conducted to examine the association between the carotid artery intima-media thickness (IMT), plaque and cardiovascular risk factors according to gender and age. METHODS: The data used for this study were obtained from 1,507 subjects (691 men, 816 women), aged 20-74 years, who participated in 'Prevalence study of thyroid diseases' in two counties of Jeollanam-do Province during July and August of 2004. The body mass index (BMI) and waist hip ratio (WHR) were calculated by anthropometry. The blood pressure, pulse rate, pulse pressure, total cholesterol, triglyceride, HDL cholesterol and fasting blood sugar level were also measured. Ultrasonography was used to measure the carotid artery IMT and plaque. IMT measurements were performed at 6 sites, including both common carotid arteries, and the bulb and internal carotid arteries. The definition of the 'mean IMT' was mean value obtained from these 6 sites. RESULTS: The mean+/- standard deviation IMT values were 0.65+/-0.14 and 0.60+/-0.13 mm in men and women (p<0.001), respectively. The data were analyzed according to gender and the 50 year age groups. In a multiple linear regression analysis, age and hypertension were positively associated with the mean IMT in both men and women, aged<50 years. Age, total cholesterol and smoking (current) were positively associated with the mean IMT in men (-50 years). Age was positively associated with the mean IMT in women (> or = 50 years), but the HDL cholesterol level was negatively associated. The prevalence of plaques was 44.2%(196/443) in men and 19.4%(89/459) in women, for those greater than 50 years of age. In a multiple logistic regression analysis, age (OR=1.090, 95%CI=1.053-1.129), HDL cholesterol (OR=0.964, 95%CI=0.944-0.984), total cholesterol (OR=1.009, 95%CI=1.002-1.017)and BMI (OR=0.896, 95%CI=0.8180.983) were independently associated with plaques in men; whereas, age (OR=1.057, 95%CI=1.012-1.103), HDL cholesterol (OR=0.959, 95%CI=0.932-0.986), pulse pressure (OR=1.029, 95%CI=1.007-1.050) and triglycerides (OR=0.531, 95%Cl=0.300-0.941) were independently associated with plaques in women. CONCLUSIONS: There were significant gender and aging differences in the association between the IMT, plaque and cardiovascular risk factors. Therefore, for the prevention of atherosclerosis, selective approaches should be considered with regard to gender and age factors.

Adult↗

PubMed1992

Prospective evaluation of a model for the prediction of milk:plasma drug concentrations from physicochemical characteristics.

1. Milk:plasma (M/P) drug concentration ratios predicted by a model utilizing pKa, plasma protein binding and octanol:water partition coefficients have been compared with actual M/P values for 10 basic drugs. 2. There was a close relationship between predicted and observed M/P ratios with a coefficient of determination r2 of 0.97. However, there was a proportional error. 3. The data were transformed by taking logs of predicted and observed (M/P + 1) values. Regression analysis resulted in an r2 of 0.95, an intercept on the Y-axis not significantly different from zero and a slope not significantly different from one. 4. The 95% confidence interval around a single prediction revealed an error between 150% for the lowest and 23% for the highest M/P ratios. The error is therefore lowest for the drugs likely to have the greatest transfer into milk. 5. There was no significant bias in the predictions. 6. The model was refined by multiple linear regression analysis utilising the observed M/P ratios for the 10 basic drugs in addition to those of the original drugs. The revised equation resulted in an improvement in the explained variance. 7. Protein binding was the most important single predictor. 8. The results confirm that M/P ratios for basic drugs can be predicted accurately from their physicochemical characteristics.

Algorithms↗

PubMed2001

Correlates of antibiotic use in Taiwan hospitals.

OBJECTIVE: To determine factors that correlate with increased antibiotic use among adult inpatients in Taiwan. DESIGN: Retrospective survey of medical records. SETTING: 14 acute-care hospitals (8 regional hospitals, 6 medical centers) in Taiwan. PARTICIPANTS: A systematic probability sample from each hospital, totaling 663 adult inpatients who were discharged or had died in early 1999. MEASUREMENTS: Infectious disease physicians at the 14 hospitals collected data from medical records regarding patient demographics, hospitalization, discharge diagnosis, and antibiotics received. RESULTS: A total of 447 (67%) patients received antibiotics for an overall rate of 813 antibiotic-days (number of days patients received each antibiotic)/1,000 patient-days. Both the proportion of beds in intensive care units ([ICUs] Pearson correlation coefficient [r], 0.67; 95% confidence interval [CI 95], 0.36-0.89; P<.01) and the proportion of patients admitted to surgical services (r, 0.66; CI 95, 0.20-0.88; P=.01) correlated with the mean patient rate of antibiotic-days/hospital-day (MPAUD). In contrast, we found no correlation between the proportion of patients who received antibiotics and the MPAUD. Using multiple linear regression, medical center status was the only independent predictor for increased MPAUD (regression coefficient [b], 0.15; CI 95, 0.05-0.24; P<.01). There was no correlation between pooled rates of antibiotic-days/hospital-day and any hospital demographic factors. First-generation cephalosporin (39%) and aminoglycoside (24%) use accounted for the majority of antibiotic-days. CONCLUSIONS: Antibiotic use is greater in medical centers than in regional hospitals and appears to be independent of surgical case mix or the proportion of ICU beds. Determination of multiple, independent measures of antibiotic use may be necessary to understand the relation between antibiotic use and resistance in hospital.

Adolescent↗

PubMed2005

An accurate VO2max nonexercise regression model for 18-65-year-old adults.

The purpose of this study was to develop a regression equation to predict maximal oxygen uptake (VO2max) based on nonexercise (N-EX) data. All participants (N = 100), ages 18-65 years, successfully completed a maximal graded exercise test (GXT) to assess VO2max (M = 39.96 mL x kg(-1) x min(-1), SD = 9.54). The N-EX data collected just before the maximal GXT included the participant's age; gender; body mass index (BMI); perceived functional ability (PFA) to walk, jog, or run given distances; and current physical activity (PA-R) level. Multiple linear regression generated the following N-EX prediction equation (R = .93, SEE = 3.45 mL x kg(-1) x min(-1), % SEE = 8.62): VO2max (mL x kg(-1) x min(-1)) = 48.0730 + (6.1779 x gender; women = 0, men = 1) - (0. 2463 x age) - (0.6186 x BMI) + (0.7115 x PFA) + (0.6709 x PA-R). Cross validation using PRESS (predicted residual sum of squares) statistics revealed minimal shrinkage (R(p) = .91 and SEE(p) = 3.63 mL x kg(-1) x min(-1)); thus, this model should yield acceptable accuracy when applied to an independent sample of adults (ages 18-65 years) with a similar cardiorespiratory fitness level. Based on standardized beta-weights, the PFA variable (0.41) was the most effective at predicting VO2max followed by age (-0.34), gender (0.33), BMI (-0.27), and PA-R (0.16). This study provides a N-EX regression model that yields relatively accurate results and is a convenient way to predict VO2max in adult men and women.

Adolescent↗

PubMed2004

Does concomitant stress incontinence alter the efficacy of tolterodine in patients with overactive bladder?

PURPOSE: Muscarinic antagonists such as tolterodine are the treatment of choice for overactive bladder (OAB). We determined the impact of concomitant stress incontinence (SI) on the therapeutic effects of tolterodine in patients with OAB with and without concomitant SI. MATERIALS AND METHODS: Data from an open label, observational study involving 2,250 patients with OAB symptoms were analyzed for baseline frequency, urgency and incontinence, and alterations in these symptoms while on 12-week treatment with 2 mg tolterodine twice daily. Data are shown as the mean +/- SD. The statistical significance of differences in treatment effects was determined by multiple regression analysis, adjusting for gender, age and baseline symptom intensity. RESULTS: Concomitant I to III degree SI according to the Stamey grading was present in 31%, 15% and 2% of patients, respectively, and it was associated with increasing basal incontinence, although only III degree SI was associated with greater baseline frequency or urgency. In the overall group tolterodine decreased frequency, urgency and urge incontinence from 12.4 +/- 4.3 to 7.7 +/- 2.7, 8.4 +/- 5.1 to 2.0 +/- 3.0 and 3.4 +/- 4.2 to 0.8 +/- 2.0 episodes daily, respectively. On multiple linear regression analysis I and II degree SI had a minor, if any, effect on this improvement, while III degree SI was statistically associated with a smaller decrease in frequency (by 1.4 +/- 0.4 micturitions daily, p = 0.0002) and incontinence (by 2.1 +/- 0.3 episodes daily, p < 0.0001) but with similar alterations in the number of urge episodes. CONCLUSIONS: Concomitant I or II degree SI has little effect on the efficacy of tolterodine in OAB cases. Only patients with concomitant III degree SI have significantly less improvement.

Aged↗

PubMed2000

Vibration perception thresholds in workers with long term exposure to lead.

OBJECTIVES: To evaluate the impact of long term occupational exposure to lead on function of the peripheral nervous system as reflected by vibration perception threshold (VPT), measured with a portable vibrameter. METHODS: 217 Workers in a lead battery factory were required to have an annual blood lead measurement during each of the 5 years preceding this study. All were invited to take the VPT test. A total of 206 workers were studied. The associations were analysed between VPTs and current blood lead concentration, mean concentration of blood lead over the past 5 years, maximum blood lead concentration during the past 5 years, index of cumulative blood lead (ICL), time weighted index of cumulative blood lead (TWICL), and percentage of lifespan spent at work in the plant, as well as the other potential confounders. Ordinary multiple regressions, generalised additive models, and hockey stick regression analyses were used to explore the potential existence of a threshold effect of blood lead variables on VPT. RESULTS: VPT at a frequency of 220 Hz ranged from 6 to 100 (10(-2) g, or 0.098 m/s(2)) with a mean (SD) of 19.8 (14.2) for the feet and from 4 to 43 with a mean (SD) of 10.2 (6.1) for the hands. The five variables of exposure to lead were all significantly correlated with VPT of the feet but not the hands. In multiple linear regression analyses, the mean of the blood lead concentrations and the TWICL were significantly associated with VPT of the feet. The relation between VPT of the feet and mean blood lead was shown to be a J shaped curve with a generalised additive model and local smoothing technique. In the hockey stick regression, evidence was found of a threshold effect at a mean blood lead concentration of 31 microgram/dl. Above this threshold it was estimated that each increase of 1 microgram/dl mean blood lead over 5 years would increase VPT of the feet by 0.29 (10(-2) g) or 0.028 m/s(2) (at a frequency of 220 Hz) with other potential confounders held constant. CONCLUSION: This study suggests that measurement of vibration sensory threshold is a relatively effective tool for detecting lead neuropathy in field studies, and that lead might cause sensory neuropathy with an effect threshold corresponding to a 5 year mean blood lead concentration of 31 microgram/dl.

Adult↗

PubMed1998

Longitudinal predictors of airway responsiveness to distilled water: the role of atopy and maternal smoke exposure.

Airway responsiveness is an objectively measurable clinical trait related to the presence of asthma. Although risk factors for this trait have been evaluated cross-sectionally, little is known about its longitudinal predictors. A population cohort of 539 children, aged 8 yrs at the start of follow-up, underwent 3-7 bronchial challenge tests spaced at 3-9 month intervals. Airway responsiveness was assessed by a single-step distilled water challenge. To investigate responsiveness as a continuous trait, the ratio of the postchallenge to prechallenge forced expiratory volume in one second was calculated. A child's repeated ratios were then regressed on the time of follow-up. The resulting child-specific regression coefficient was the outcome variable to assess longitudinal predictors of airway responsiveness (AR). Results were based on 2,267 repeated challenge tests, and indicated an overall decrease in responsiveness. Children with a diagnosis of asthma (mean+/-SD, longitudinal change in AR + yr(-1): -0.060+/-0.149), those with a positive skin-prick test (-0.018+/-0.106) and those with reported exposure to maternal smoking (-0.004+/-0.083) demonstrated increased airway responsiveness over time. All of these changes in airway responsiveness were found to be significant in multiple linear regression analysis (p<0.05). Stratified analysis further indicated that the effect of maternal smoking was observed primarily in nonatopic children and was greatest at an exposure level of > or =10 cigarettes x day(-1). In conclusion, atopy and exposure to maternal smoking can predict longitudinal change in childhood airway responsiveness.

Air Pollutants↗

PubMed2026

Persistent trauma three decades after the Halabja massacre: psychological symptom profiles and hair cortisol levels in gas attack survivors.

BACKGROUND: Survivors of the 1988 Halabja chemical attack have experienced severe, chronic trauma, yet limited research has examined the long-term psychological and biological consequences of chemical warfare exposure more than three decades later. AIMS: To examine long-term post-traumatic stress disorder (PTSD) symptoms, depression/anxiety symptoms, somatic symptoms and perceived stress among survivors of the Halabja chemical attack, and to investigate the associations of trauma exposure, sociodemographic factors and hair cortisol concentrations (HCCs) with psychological symptom severity and symptom profiles. METHOD: A total of 209 survivors of the Halabja chemical attack participated in structured interviews using culturally adapted and field-tested instruments, including the Post-Traumatic Stress Disorder Checklist for DSM-5, Hopkins Symptom Checklist-25, the Patient Health Questionnaire-13, the Perceived Stress Scale-14 and an adapted War and Adversity Exposure Checklist-26. Hair cortisol and cortisone concentrations were assessed as biomarkers of chronic stress. Data were analysed using correlations, independent-samples t-tests, multiple linear regression analyses, multinomial logistic regression and latent profile analysis (LPA). RESULTS: Survivors demonstrated a substantial long-term psychological symptom burden. Overall, 87.6% of participants exceeded the cut-off for probable PTSD symptoms, and 75.1% exceeded the cut-off for elevated depression/anxiety symptoms. Most participants (81.8%) reported exposure to 11 or more lifetime traumatic events. Men reported significantly greater cumulative trauma exposure, whereas women reported significantly greater somatic symptom severity. Higher educational attainment and employment were consistently associated with lower psychological symptom severity across multiple outcomes. HCCs were not significantly associated with PTSD symptoms or latent symptom-profile membership after adjustment for trauma exposure and psychosocial variables. The LPA identified four symptom-severity classes characterised by differing levels of PTSD and depression/anxiety symptoms. Greater cumulative trauma exposure and lower social support were associated with membership in more severe symptom classes. CONCLUSIONS: Survivors of the Halabja chemical attack continue to experience substantial psychological distress more than three decades after exposure. Long-term symptom severity appears to be more strongly associated with cumulative trauma exposure and psychosocial adversity than with HCCs. The findings highlight substantial heterogeneity in symptom presentation and support the need for long-term, culturally sensitive and trauma-informed mental health interventions for survivors of chemical warfare and mass violence.

Halabja chemical attack↗

PubMed1996

Apical root resorption in orthodontically treated adults.

This study analyzed the relationship in orthodontically treated adults between upper central incisor displacement measured on lateral cephalograms and apical root resorption measured on anterior periapical x-ray films. A multiple linear regression examined incisor displacements in four directions (retraction, advancement, intrusion, and extrusion) as independent variables, attempting to account for observed differences in the dependent variable, resorption. Mean apical resorption was 1.36 mm (sd +/- 1.46, n = 73). Mean horizontal displacement of the apex was -0.83 mm (sd +/- 1.74, n = 67); mean vertical displacement was 0.19 mm (sd +/- 1.48, n = 67). The regression coefficients for the intercept and for retraction were highly significant; those for extrusion, intrusion, and advancement were not. At the 95% confidence level, an average of 0.99 mm (se = +/- 0.34) of resorption was implied in the absence of root displacement and an average of 0.49 mm (se = +/- 0.14) of resorption was implied per millimeter of retraction. R2 for all four directional displacement variables (DDVs) taken together was only 0.20, which implied that only a relatively small portion of the observed apical resorption could be accounted for by tooth displacement alone. In a secondary set of univariate analyses, the associations between apical resorption and each of 14 additional treatment-related variables were examined. Only Gender, Elapsed Time, and Total Apical Displacement displayed statistically significant associations with apical resorption. Additional multiple regressions were then performed in which the data for each of these three statistically significant variables were considered separately, with the data for the four directional displacement variables. The addition of information on Elapsed Time or Total Apical Displacement did not explain a significant additional portion of the variability in apical resorption. On the other hand, the addition of information on Gender to the information on the four directional displacement variables yielded an R2 value of 0.35, which indicated that these variables taken together could account for approximately a third of the observed variability in apical resorption in this sample.

Adult↗

PubMedDate not supplied

Estimation of age at death by tibial osteon remodeling in an autopsy series.

Estimation of age at death by histological methods in tibiae has been found to be inaccurate in individuals less than 55 years of age. This study describes reasons for the inaccurate age estimates and provides a new regression equation for age estimation. Bone cores were removed from tibiae in 53 individuals at autopsy ranging in age from 17 years to 53 years of age; 48 males and 5 females. The sample contained 41 whites and 12 blacks. Variables ascertained from each core were: cortical thickness, cortical bone density, secondary osteon number, area, and perimeter, and Haversian canal area and perimeter. The results showed significant differences in secondary osteon number, area, and perimeter between groups aged less than and greater than 35 years of age. Multiple linear regression analysis indicated osteon number to be the best predictor of age in this sample aged less than 55 years of age. Age at death was accurately estimated for 11 additional forensic cases using osteon number in tibiae. No significant histological differences were observed between males and females and between blacks and caucasians.

Adolescent↗

PubMed2006

Beliefs about the appropriate age for initiating toilet training: are there racial and socioeconomic differences?

OBJECTIVE: To examine racial and socioeconomic differences in parental beliefs about the appropriate age at which to initiate toilet training. STUDY DESIGN: A cross-sectional survey of 779 parents visiting child health providers in 3 clinical sites in Washington, DC and the surrounding metropolitan area completed a self-report survey. The main outcome variable was parental beliefs about the appropriate age at which to initiate toilet training. Using multiple linear regression, differences in beliefs were assessed in relation to race, family income, parental education, parental age, and age of the oldest and youngest children. RESULTS: Among respondents, parents felt that the average age at which toilet training should be initiated was 20.6 months (+/-7.6 months), with a range of 6 to 48 months. Caucasian parents believed that toilet training should be initiated at a significantly later age (25.4 months) compared with both African-American parents (18.2 months) and parents of other races (19.4 months). In the multiple regression model, factors predicting belief in when to initiate toilet training were Caucasian race and higher income. CONCLUSIONS: Race and income were independent predictors of belief in age at which to initiate toilet training. More research is needed to determine what factors contribute to toilet training practices in diverse populations.

Black or African American↗