Cognitive behavioral therapy of minor depressive symptoms in elderly Chinese Americans: a pilot study

There is a high prevalence of suicide among elderly Chinese, and particularly among elderly Chinese women in Mainland China with a prevalence of 19.6 per hundred thousand. Since Chinese individuals may much more highly value education, a cognitive-behavioral package originated by Ricardo Munoz, Ph.D. was adapted for Chinese American subjects. The material was videotaped in eight sessions, approximately 25 minutes in length, to be shown to community subjects who were at least 40 years and over. In addition, a videotape of muscular relaxation techniques was made. A manual written in Chinese about the content of each class, was given to each subject when he/she attended. The experimental group showed significant improvement in the scores in the Hamilton Depression Scale, including the Somatic Subscale in the Hamilton Anxiety Scale. There was no significant improvement in the control group on any of the measures. Thus the study suggests the efficacy of psychoeducational classes in reducing symptoms of depression in non-patient community elderly. Other studies are being conducted among Korean Americans and Japanese Americans in the United States, and also in the Orient among Japanese elderly.

Performance of a general location model with an ignorable missing-data assumption in a multivariate mental health services study

In a study of the impact of case management teams in a publicly funded mental health programme, mental health patients were interviewed about a variety of outcomes suggestive of successful community adaptation, such as support from family and friends and avoidance of legal problems. Because outcome data were missing for a number of patients, a follow-up study was carried out to obtain this information form previous non-responders whenever possible. Because the data of interest were multivariate and included both continuous and categorical variables, a candidate approach for handling incomplete data in the absence of follow-up data would have been to fit a general location model, presumably with log-linear constraints on cell probabilities to avoid overfitting of the data. Here, we use available follow-up data to investigate the performance of a series of general location models with ignorable non-response. We note some problems with this approach and embed the discussion of this example in a broader consideration of the role of ignorable and non-ignorable models in applied research.

Psychotropic medication use among children in foster care: relationship to severe psychiatric disorders

OBJECTIVES

This study sought to describe the level of psychotropic medication use and its relationship to severe psychiatric disorders among school-aged children in foster care.

METHODS

Home interviews with 302 foster parents and children aged 6 to 12 years and 266 follow-up clinical evaluations were conducted.

RESULTS

Thirteen percent of the children had taken psychotropic medication in the previous year, and 52% of those whose clinical status merited a medication evaluation had not received medication in the previous year.

CONCLUSIONS

As the efficacy of psychotropic medication treatment for severe child psychiatric disorders becomes more established, research on the appropriateness of such care can begin.

Psychotropic medication treatment patterns among school-aged children in foster care

This study describes the level of psychotropic medication use and patterns of such treatment among school-aged children in foster care. Structured survey interviews were conducted in the foster homes of 302 randomly selected children, aged 6-12 years, who were living in foster care for 6 months or more and placed from three county service areas. Follow-up mental health assessments using the existing system of care format were completed on 255 children. Sixteen percent of these school-aged children in foster care were found to have taken psychotropic medication during their lifetime. The most common class of medication used in the past year was stimulants (62%). Children who were older, from Caucasian and biracial backgrounds, and who lived in a group home more likely to have taken psychotropic medication in the past year. Among those children who received a clinician diagnosis of a severe psychiatric disorder for which medication is an accepted component of care, boys were more likely to receive medication treatment than girls. Sociodemographic characteristics and placement history variables may be influential in the level of psychotropic medication use among this population. Further research to examine the appropriateness and level of benefit of medication treatment in this population is needed.

General neurologist and subspecialist care for multiple sclerosis: patients' perceptions

OBJECTIVE

To compare general neurologists and MS specialists on patients' clinical characteristics and MS care as perceived by patients with MS.

METHODS

We sampled all adult patients with MS having physician visits over a 2-year period from a Midwestern managed-care organization and from the fee-for-service portion of 23 randomly selected California neurologists' practices. In mid-1996, 694 subjects were mailed questionnaires; 532 (77%) responded. Sociodemographic/clinical characteristics, recent utilization of services/treatments, unmet needs, symptom care, and research participation were measured. Of 502 subjects (94%) who indicated their usual physician providing MS care was a neurologist, 217 (43%) reported having a general neurologist and 285 (57%) reported having an MS specialist. Comparisons between these two groups were adjusted for comorbidity and disease severity.

RESULTS

General neurologist and MS specialist patient groups did not differ on any sociodemographic or clinical characteristic except age (p<0.05). Although health care utilization generally was similar, higher proportions of the MS specialist group were aware of or had discussed interferon beta-1b (IFNbeta-1b) with their physician (p<0.05) and were currently taking it (p<0.05); a smaller proportion of the MS specialist group reported stopping it because of side effects (p<0.01). Overall, levels of unmet need and care for recent symptoms were similar, but the MS specialist group reported more confidence in their physician/carefulness in listening (p<0.05). Twice as many MS specialist subjects had participated in nondrug research (p<0.05); drug study participation was similar.

CONCLUSIONS

Patients' perceptions of their care were similar in most ways for those who designated their main MS provider as a general neurologist compared to an MS specialist; however, care differed in potentially important areas. Prospective, longitudinal studies are needed to measure and relate neurologists' training, experience, knowledge, and MS patient volume with both process and outcome measures of quality of MS care.

Predictors of sexual health in women after a breast cancer diagnosis

PURPOSE

To identify variables that might be predictive of sexual health (interest, dysfunction, and satisfaction) in a large sample of breast cancer survivors, with a validation conducted in a second, independent sample.

PATIENTS AND METHODS

On the basis of a conceptual framework of sexual health in breast cancer survivors, we performed multivariable regression analyses to estimate sexual interest, dysfunction, and satisfaction in both samples. Additional analyses were performed using stepwise regression and recursive partitioning to explore in each sample the relative contributions of the independent variables toward predicting the outcome measures.

RESULTS

The models for sexual interest accounted for at least 33% of the variance, and the significant predictors common to the two samples were having a new partner since the diagnosis of breast cancer, mental health score, and body image score. For sexual dysfunction, the models in the two samples explained at least 33% of the variance, and the common significant predictors were vaginal dryness, past chemotherapy use, and having a new partner since diagnosis. The sexual satisfaction models explained at least 27% of the variance, with the common significant predictors being the quality of the partnered relationship and sexual problems in the partner.

CONCLUSION

Among the predictors of sexual health, several are mutable (vaginal dryness, emotional well-being, body image, the quality of the partnered relationship, and sexual problems in the partner), and these should be considered for future interventions to address the sexual health and well-being of breast cancer survivors.

Pharmacological and psychological treatments for depressed older patients: a meta-analysis and overview of recent findings

A meta-analysis was carried out to evaluate data published between January 1974 and February 1998 comparing rates of treatment response and tolerability of pharmacological and psychological treatments for depression in persons over age 55. Drugs (tricyclic antidepressants, selective serotonin-reuptake inhibitors, and a mixed group of other drugs) were significantly better than placebo, with an average reduction in symptom severity of 48.0% versus 31.3% (analysis weighted by sample size; 50.6% vs. 21.4% unweighted). No single drug or group of drugs was superior in terms of efficacy, and no statistically significant differences in tolerability emerged between tricyclic antidepressants and selective serotonin-reuptake inhibitors, whether measured by total dropouts or by dropouts due to side effects. Compared to the data on pharmacological treatments, those for outcomes of psychological treatments are very limited. Existing data indicate that cognitive-behavioral, behavioral, and psychodynamic therapies are significantly better than placebo. In the current meta-analysis, response rates to these nondrug therapies did not differ significantly from those observed with tricyclic antidepressants or selective serotonin-reuptake inhibitors, but direct comparison data are insufficient for firm conclusions to be drawn about comparative efficacy. It is possible, even likely, that not only different subtypes of depression but also different patients vary in their treatment responses. However, lack of adequate data prevented the current meta-analysis from addressing these issues. Rigorously designed prospective studies on treatment outcome, taking into account the above differences, are urgently needed to provide robust data on which to base clinical recommendations for the treatment of depression in older patients.

Psychosocial stressors among sheltered homeless children: relationship to behavior problems and depressive symptoms

Level of exposure to severe psychosocial stressors was assessed among homeless children in emergency family shelters in an urban locale. The relationship between such exposure and child mental health problems was then investigated, along with the effects of adult family social support. Implications of the findings are discussed.

Differential access to care for children with ADHD in special education programs

Access to treatment for children with attention-deficit hyperactivity disorder (ADHD) was examined in the general health, specialty mental health, and informal care sectors. Special education students in a Florida school district were screened for ADHD, and high-risk children and their parents completed diagnostic and services assessment interviews. Female gender, minority status, and rural residence lowered the probability of ADHD service use in the general health sector. Use of services in the mental health and informal sectors was predicted by a child's need for services. Further study is needed to identify barriers to service use at the parental or gatekeeper level for this common disorder among children.

Intermittent calcitriol therapy in secondary hyperparathyroidism: a comparison between oral and intraperitoneal administration

BACKGROUND

Intermittent oral or intravenous doses of calcitriol given two or three times per week are commonly used to treat secondary hyperparathyroidism (secondary HPT). This study was undertaken to compare the biochemical and skeletal responses to thrice weekly intraperitoneal (i.p.) versus oral doses of calcitriol in children with secondary HPT undergoing peritoneal dialysis (CCPD).

METHODS

Forty-six patients aged 12.5+/-4.8 years on CCPD for 22+/-25 months were randomly assigned to treatment with oral (p.o.) or i.p. calcitriol for 12 months; 17 subjects given p.o. calcitriol and 16 subjects given i.p. calcitriol completed the study. Bone biopsies were performed at the beginning and at the end of the study, while determinations of serum and total ionized calcium, phosphorus, alkaline phosphatase, parathyroid hormone (PTH) and calcitriol levels were done monthly.

RESULTS

Serum total and ionized calcium levels were higher in subjects treated with i.p. calcitriol, P < 0.0001, whereas serum phosphorus levels were higher in those given p.o. calcitriol, P < 0.0001. For the i.p. group, serum PTH levels decreased from pre-treatment values of 648+/-125 pg/ml to a nadir of 169+/-57 pg/ml after nine months. In contrast, serum PTH levels did not change from baseline values of 670+/-97 pg/ml in subjects given p.o. calcitriol, P < 0.0001 by multiple regression analysis. Serum alkaline phosphatase levels were also lower in patients treated with i.p. calcitriol, P < 0.0001, but there was no difference between groups in the average dose of calcitriol given thrice weekly. The skeletal lesions of secondary HPT improved in both groups, 33% of patients developed adynamic bone lesion.

CONCLUSION

Differences in the bioavailability of calcitriol and/or in phosphorus metabolism may account for the divergent biochemical response to p.o. and i.p. calcitriol.

Variations in ADHD treatment among special education students

OBJECTIVE

To examine variation in patient characteristics (case-mix) and treatment patterns for attention-deficit/hyperactivity disorder (ADHD) by provider type.

METHOD

By means of a two-stage study design, 102 children were identified as receiving treatment for ADHD in the past year, among a school district-wide sample of second-through fourth-grade special education students. Parent and child interviews were conducted using standardized measures of need for treatment, service use, and process of care.

RESULTS

Nearly three fourths of the children received treatment for ADHD by a primary care provider, and of these, 68% did not have any contact with a mental health specialist. Children treated only by a primary care provider had fewer comorbid conditions, less impairment, and lower levels of family burden than children treated only by a mental health specialist. Treatment of ADHD solely by primary care providers was characterized by fewer sessions, less time with the patient, and less use of multimodal therapies.

CONCLUSION

Future studies examining clinical outcomes for ADHD treatment should take into account variation in case-mix and treatment patterns by provider type.

Calcium-sensing by parathyroid glands in secondary hyperparathyroidism

Calcium-sensing by the parathyroids is abnormal in familial benign hypocalciuric hypercalcemia and in primary hyperparathyroidism (primary HPT), but the role of a calcium-sensing defect in uremic secondary hyperparathyroidism (secondary HPT) remains controversial. To study the regulation of PTH release by calcium, set point estimates were obtained using the four parameter model during in vivo dynamic tests of parathyroid gland function in 31 patients with secondary HPT, 8 patients with advanced secondary HPT studied shortly before undergoing parathyroidectomy (Pre-PTX), 3 patients with primary HPT, and 20 subjects with normal renal function (NL); the response to 2-h i.v. calcium infusions was also evaluated. Neither blood ionized calcium (iCa+2) levels nor the set point for calcium-regulated PTH release differed between secondary HPT and NL; iCa+2 levels and set point values were moderately elevated in Pre-PTX and markedly elevated in primary HPT. Compared with values obtained in NL, the lowest serum PTH levels achieved during calcium infusions, expressed as a percentage of pre-infusion values, were incrementally greater in secondary HPT, Pre-PTX, and primary HPT, whereas the slope of the relationship between iCa+2 and PTH, expressed as the natural logarithm (ln) of percent preinfusion values, decreased incrementally in secondary HPT, Pre-PTX, and primary HPT. The inhibitory effect of calcium on PTH release is blunted both in secondary HPT and primary HPT because of increases in parathyroid gland mass, but a calcium-sensing defect is a late, rather than early, consequence of renal secondary HPT.

Children in special education programs: attention deficit hyperactivity disorder, use of services, and unmet needs

OBJECTIVES

Attention deficit hyperactivity disorder (ADHD), a common psychiatric condition, may impair a child's ability to learn and to form social relationships, tasks critical to healthy development. This study describes the prevalence of the disorder among children in special education programs and identifies the extent and predictors of unmet service needs.

METHODS

A 2-stage screening protocol of a countywide population of second- through fourth-grade students in special education was conducted to (1) screen for ADHD, employing standardized parent and teacher questionnaires, and determine health services use (n = 499) and (2) perform diagnostic assessments of ADHD (n = 318).

RESULTS

Almost half of the children qualified for a diagnosis of ADHD, yet only half of those were reportedly receiving care for the condition, mainly in the general health care sector. Girls were more than 3 times as likely as boys to have unmet service needs; minority status, low income, and health maintenance organization coverage also emerged as possible risk factors for unmet service needs.

CONCLUSIONS

ADHD is a common yet often untreated condition among children in special education. Mental health services for children with this disorder should be integrated with general health care and special education programs.

Practice styles of US compared to UK neurologists

OBJECTIVE

This study assessed variation between neurologists in the United States and United Kingdom in their diagnostic and treatment decisions for commonly encountered neurologic presentations, and identified explanatory factors for any observed variation.

METHODS

All 210 consultant neurologists in the United Kingdom and a nationally representative sample of 595 US neurologists received mailed surveys containing three detailed clinical scenarios depicting patients with (1) a single unprovoked seizure occurring 3 days previously, (2) early Parkinson's disease, and (3) dementia. The main study outcome measures were self-reported decisions regarding diagnostic test ordering and treatment, which were assessed after each scenario. Neurologists' practice characteristics, certainty about the diagnosis, and attitudes toward uncertainty were also measured. Survey response rates were 92% of US and 63% of UK neurologists.

RESULTS

A higher proportion of US than UK neurologists indicated they would order additional diagnostic tests for all three scenarios (all p < 0.05); 77% of UK compared with 26% of US neurologists would manage a single unprovoked seizure without antiepileptic medication (p < 0.0001), but treatment of early Parkinson's disease was not different. Nearly all US and UK neurologists would obtain a neuroimaging study in the evaluation of dementia. International differences persisted after adjustment for differences in demographic and practice characteristics and for attitudes toward test use and clinical uncertainty.

CONCLUSIONS

We identified large international variation in clinical decisions across three common neurologic conditions. Cross-country collaboration should explore these differences to develop consensus on standards of care.

D2 and D4 dopamine receptor polymorphisms and personality

The relationship of various dimensions of temperament, measured by the Tridimensional Personality Questionnaire (TPQ), to polymorphisms of the D2 dopamine receptor (DRD2) and D4 dopamine receptor (DRD4) genes was determined in 119 healthy Caucasian boys who had not yet begun to consume alcohol and other drugs of abuse. Total Novelty Seeking score of the TPQ was significantly higher in boys having, in common, all three minor (A1, B1, and Intron 6 1) alleles of the DRD2 compared to boys without any of these alleles. Boys with the DRD4 7 repeat (7R) allele also had a significantly higher Novelty Seeking score than those without this allele. However, the greatest difference in Novelty Seeking score was found when boys having all three minor DRD2 alleles and the DRD4 7R allele were contrasted to those without any of these alleles. Neither the DRD2 nor the DRD4 polymorphisms differentiated total Harm Avoidance score. Whereas subjects having all three minor DRD2 alleles had a significantly higher Reward Dependence 2 (Persistence) score than subjects without any of these alleles, no significant difference in this personality score was found between subjects with and without the DRD4 7R allele. In conclusion, DRD2 and DRD4 polymorphisms individually associate with Novelty Seeking behavior. However, the combined DRD2 and DRD4 polymorphisms contribute more markedly to this behavior than when these two gene polymorphisms are individually considered.

Paroxetine treatment of aggression and self-injury in persons with mental retardation

An open, prospective assessment of the treatment of severe aggression and self-injurious behavior (SIB) with paroxetine, a serotonin re-uptake inhibitor, in 15 institutionalized persons with mental retardation was undertaken. Frequency and severity of aggression and SIB were charted by trained staff members. Only aggression severity was reduced over the entire 4-month follow-up period. Within the limits of an open trial, this effect was significant at one month but did not remain significant subsequently. The apparent diminution of effectiveness after 4 weeks of treatment may suggest adaptive changes warranting further study.

Diagnostic utility of two commonly used ADHD screening measures among special education students

OBJECTIVE

To examine the diagnostic utility of two commonly used attention-deficit hyperactivity disorder (ADHD) screening measures in a population of special education students and address whether screener performance is affected by demographic characteristics.

METHOD

A school district population of special education students was screened for ADHD risk using two parent questionnaires, the 46-item Attention Deficit Disorders Evaluation Scale (ADDES) and the 10-item Conners Abbreviated Symptom Questionnaire (ASQ). All high-risk children and a random sample of low-risk children subsequently underwent DSM-IV-based diagnostic assessment through parental diagnostic interviews (Diagnostic Interview Schedule for Children Version 3.0). Diagnostic utility was summarized by sensitivity, specificity, predictive utilities of positive and negative tests, and efficiency, all of which were estimated using an approach that accounted for the sampling design.

RESULTS

Overall efficiency scores ranged between 70% and 74%. Sensitivity estimates were below 70% even at low screener cutoff scores. The ADDES did not perform significantly better than the ASQ. Significant gender and ethnicity effects emerged.

CONCLUSIONS

Overall, both the ASQ and the ADDES yielded substantial numbers of false positives and false negatives among this population of children, indicating that alternative approaches will be required to accurately and efficiently identify children in need of services for ADHD. Child psychiatrists can play a valuable consulting role as school districts and primary care settings struggle to implement appropriate identification procedures for ADHD.

Psychological distress and treatment adherence among children on dialysis

Among 23 pediatric renal dialysis patients, we obtained self-reported assessments of psychological adjustment and biochemical and subjective ratings of adherence. Findings indicate elevated levels of depressive symptoms and substantial nonadherence. Depressive symptoms were associated with higher levels of hopelessness, more negative self-perceptions, and more depressogenic attributional style. The psychological adjustment measures did not significantly correlate with adherence. Nonsignificant associations among different measures of adherence underscore its multifaceted nature. Implications for monitoring the adjustment of children on dialysis, assessing adherence, and future research are discussed.

Suppressive effect of calcium on parathyroid hormone release in adynamic renal osteodystrophy and secondary hyperparathyroidism

Serum parathyroid hormone (PTH) levels are markedly lower in patients with the adynamic lesion (AD) of renal osteodystrophy than in those with secondary hyperparathyroidism (2 degrees HPT), but serum PTH values are often moderately elevated in AD when compared to subjects with normal renal and parathyroid gland function (NL). To study the inhibitory effect of calcium on PTH release in AD and in 2 degrees HPT, the response to two-hour intravenous calcium infusions was examined in 6 patients with AD, in 31 patients with 2 degrees HPT and in 20 NL. Basal serum PTH levels were 88 +/- 51, 536 +/- 395, and 26 +/- 6 pg/ml, respectively, in AD, 2 degrees HPT and NL, whereas basal ionized calcium levels did not differ. When expressed as a percentage of pre-infusion values, PTH levels at the end of two-hour calcium infusions were higher both in AD (23.2 +/- 5.6%) and in 2 degrees HPT (27.8 +/- 12.3%) than in NL, (11.9 +/- 5.8%, P < 0.001). Both the amplitude of suppression (%) and the rate of decline (min-1) in serum PTH were less in AD and 2 degrees HPT than in NL, P < 0.05 for each parameter; corresponding values for each group, with 95% confidence intervals, were 77% (73 to 82) and 0.039 min-1 (0.030 to 0.048) in AD, 72% (68 to 76) and 0.031 min-1 (0.025 to 0.036) in 2 degrees HPT and 87% (84 to 89) and 0.070 min-1 (0.058 to 0.089) in NL. Neither variable differed between AD and 2 degrees HPT. Basal and nadir serum PTH levels were highly correlated: r = 0.95 and P < 0.05 in AD; r = 0.90 and P < 0.01 in 2 degrees HPT; r = 0.75 and P < 0.01 in NL. The slope of this relationship was less, however, both in AD and in 2 degrees HPT than in NL, P < 0.05 by analysis of co-variance. Thus, serum PTH levels fell below 20% of pre-infusion values in fewer subjects with AD (1 of 6) or 2 degrees HPT (9 of 31) than in NL (17 of 20) (chi 2 = 17.81, P < 0.005). The results indicate that the inhibitory effect of calcium on PTH release in vivo does not differ in AD and 2 degrees HPT despite marked differences in basal serum PTH levels. Variations in functional parathyroid gland mass rather than disturbances in calcium-sensing by the parathyroids probably account not only for the lower basal serum PTH levels in patients with AD compared to those with 2 degrees HPT, but also for the moderately elevated serum PTH values commonly seen in patients with AD.

In vivo assessments of calcium-regulated parathyroid hormone release in secondary hyperparathyroidism

In vivo dynamic tests of parathyroid gland function have provided useful information about the secretory behavior of parathyroids in various clinical disorders, but the limitations of this approach must be recognized when applied to studies of parathyroid gland physiology. Set point abnormalities have been documented in vivo both in primary hyperparathyroidism and in familial hypocalciuric hypercalcemia. Such findings are consistent with in vitro results obtained in studies of dispersed parathyroid cells from patients with primary hyperparathyroidism and with recently described alteration in calcium receptor expression in patients with FHH. The assessment of parathyroid gland function in patients with end-stage renal disease presents distinct methodological problems, however, because of marked variation in the degree of parathyroid gland enlargement. Neither the four parameter model originally used to describe set point abnormalities both in vitro and in vivo or alternative approaches to the assessment of PTH secretion in vivo adequately address this important issue. Results from recent in vivo studies of patients with chronic renal failure do not support the view that the set point for calcium-regulated PTH release is abnormal in secondary hyperparathyroidism or that treatment with calcitriol lowers the set point for calcium-regulated PTH release in patients with uremic secondary hyperparathyroidism. The concept of set point disturbances has strongly influenced discussions about the pathogenesis of secondary hyperparathyroidism, and it has served as a focal point for examining the therapeutic response to calcitriol in patients with this disorder. This matter requires careful reconsideration, however, in light of recent clinical findings and the development of techniques to directly assess the molecular mechanisms responsible for regulating calcium-mediated PTH release in renal failure and other disorders of mineral metabolism. Although knowledge in this area remains limited, the extent of parathyroid hyperplasia and the role of factors that influence the development of parathyroid gland enlargement may ultimately prove to be particularly important modifiers of parathyroid gland function in chronic renal failure.

A randomized, placebo-controlled trial of calcium supplementation for decreased bone density in corticosteroid-using patients with inflammatory bowel disease: a pilot study

BACKGROUND

Patients with inflammatory bowel disease (IBD) have a high prevalence of osteoporosis. A number of studies have found that corticosteroid use is associated with the development of osteoporosis in these patients. Calcium supplementation may be of benefit in corticosteroid-induced osteoporosis and calcium may be a nutrient that patients with IBD lack.

AIM

To test the benefit of calcium supplementation on bone density in a pilot study over a 1-year period, in a group of corticosteroid-using patients with IBD, in a randomized, double-blind, placebo-controlled treatment study.

METHODS

Corticosteroid-using patients with IBD including males over the age of 18 years and premenopausal females, were randomized to receive either calcium carbonate 1000 mg plus vitamin D 250 IU (Oscal) or an identically matched placebo. Dual energy X-ray absorptiometry measurements of bone density were obtained at entry and at 1 year. At entry, and every 3 months thereafter, serum was collected for the measurement of haemoglobin, biochemistry and bone hormones. Simultaneously a 24-h urine collection was analysed for calcium excretion and creatinine clearance, and a 4-day food record was collected to document dietary calcium and vitamin D ingestion.

RESULTS

We found a high prevalence of moderately severe decreased bone density in corticosteroid-using patients with IBD. The dose of prednisone in the year prior to study entry was inversely correlated with bone density at the hip (R = -0.67, P = 0.004). At study entry serum osteocalcin was inversely correlated with corticosteroid dose in the year prior to the study (R = -0.64, P = 0.02) and at study end, directly correlated with the percentage change in spine bone density (R = 0.59, P = 0.01). The dietary calcium intake of these patients was close to the current RDA (recommended daily intake) for premenopausal, post-adolescent adults. Calcium supplementation with small extra doses of vitamin D conferred no obvious benefit to bone density at the end of 1 year. There was no correlation between oral calcium ingestion and bone mass measurements. Both the treatment and placebo groups' bone density remained relatively stable at 1 year, suggesting that bone loss in corticosteroid-using patients may peak early into the use of the corticosteroids.

CONCLUSIONS

Calcium supplementation (1000 mg/day) conferred no significant benefit to bone density at 1 year in patients with corticosteroid-using IBD patients with osteoporosis. Future investigations should explore other therapeutic avenues that may have greater effects on increasing bone density in patients who already have considerable osteoporosis.

Calcium-regulated parathyroid hormone secretion in adynamic renal osteodystrophy

Hypercalcemia and low serum parathyroid hormone (PTH) levels are features of the adynamic lesion (AD) of renal osteodystrophy, but there is little information about parathyroid gland function in this disorder. Therefore, the four parameter model was used to evaluate calcium-regulated PTH release in patients with either adynamic bone or secondary hyperparathyroidism (OF) as documented by bone biopsy and in normal volunteers (NL). Patients had undergone CCPD for 20 +/- 4.2 months, and all received calcium carbonate as the sole phosphate-binding agent. During two hours infusions of sodium citrate, the rate of decline in serum ionized calcium levels did not differ among groups; serum PTH levels rose from 136 +/- 38 to 342 +/- 140 pg/ml in AD and from 691 +/- 99 to 869 +/- 121 pg/ml in OF. Maximum PTH levels were 322 +/- 42% of baseline values in AD but only 146 +/- 9.7% of baseline in OF (P < 0.001), and the increase above baseline levels in AD did not differ from that in NL (300 +/- 25%, NS). During calcium infusions, serum PTH levels fell from 164 +/- 75 to 39 +/- 11 pg/ml in AD and from 622 +/- 76 to 171 +/- 29 pg/ml in OF; minimum serum PTH levels, expressed as a percentage of pre-infusion values, were 25 +/- 2% in AD and 26 +/- 5% in OF (NS).(ABSTRACT TRUNCATED AT 250 WORDS)

The analysis of repeated-measures data on schizophrenic reaction times using mixture models

Reaction times for schizophrenic individuals in a simple visual tracking experiment can be substantially more variable than for non-schizophrenic individuals. Current psychological theory suggests that at least some of this extra variability arises from an attentional lapse that delays some, but not all, of each schizophrenic's reaction times. Based on this theory, we pursue models in which measurements from non-schizophrenics arise from a normal linear model with a separate mean for each individual, whereas measurements from schizophrenics arise from a mixture of (i) a component analogous to the distribution of response times for non-schizophrenics and (ii) a mean-shifted component. We fit four mixture models within this framework, where the distinctions between models arise from assumptions about the variance of the shifted observations and the exchangeability of schizophrenic individuals. Some of these models can be fit by maximum likelihood using the EM algorithm, and all can be fit using the ECM algorithm, where the covariance matrices associated with the parameters are calculated by the SEM and SECM algorithms, respectively. Bayesian model monitoring using posterior predictive checks is invoked to discard models that fail to reproduce certain observed features of the data and to stimulate the development of better models.

Calcitriol therapy and calcium-regulated PTH secretion in patients with secondary hyperparathyroidism

Calcitriol lowers serum parathyroid hormone (PTH) levels in patients with secondary hyperparathyroidism, but its effect on calcium-regulated PTH release remains controversial. Thus 11 patients with secondary hyperparathyroidism underwent dynamic tests of parathyroid function before and after 4 mo of intermittent calcitriol therapy. Serum calcitriol levels rose from 8 +/- 1 to 55 +/- 9 (SE) pg/ml, P < 0.01, serum total and ionized calcium levels increased, and serum PTH levels decreased from 584 +/- 154 to 154 +/- 31 pg/ml, P < 0.05. The maximum increase in serum PTH during hypocalcemia did not differ before (248 +/- 78 pg/ml) or after (280 +/- 100 pg/ml) treatment, but the increase in PTH, expressed as a percentage of preinfusion values, was greater after treatment (329 +/- 73 vs. 132 +/- 10%, P < 0.05). The decreases in serum PTH during calcium infusions did not differ before (70 +/- 5%) or after (73 +/- 5%) therapy, and the set point for PTH release did not change (1.20 +/- 0.03 vs. 1.23 +/- 0.01 mmol/l, not significant). Calcitriol modifies PTH secretion during hypocalcemia in secondary hyperparathyroidism without affecting the set point for PTH release; although calcitriol lowers serum PTH levels, it may also restore the secretory reserve of hyperplastic parathyroid tissues during hypocalcemia.

Development of adynamic bone in patients with secondary hyperparathyroidism after intermittent calcitriol therapy

Intermittent calcitriol therapy is commonly used to treat secondary hyperparathyroidism in patients undergoing regular dialysis, but there is little available information about the histologic response of bone to this form of therapy. Accordingly, 14 children and adolescents with biopsy-proven secondary hyperparathyroidism were treated with intermittent oral or intraperitoneal doses of calcitriol for 12 months. Biochemical indices of mineral metabolism including serum intact PTH levels were measured monthly throughout the study, and bone biopsies were repeated at the end of treatment. Before treatment, 11 patients had osteitis fibrosa and three had mild lesions of secondary hyperparathyroidism. Histologic improvement was seen in 12 of 14 patients, and osteitis fibrosa resolved in 10 of 11 cases. Bone formation decreased in all patients during intermittent calcitriol therapy, falling from 861 +/- 380 to 150 +/- 170 microns2/mm2/day, P < 0.001. Bone formation decreased to normal in six patients, but six patients developed adynamic lesions of bone with subnormal bone formation rates. Serum PTH and alkaline phosphatase levels declined in those who developed adynamic bone, but values remained elevated in patients with normal rates of bone formation at follow-up evaluation. Neither the mean dose of calcitriol nor the average dose per kilogram body weight differed in patients with adynamic lesions. Thus, adynamic renal osteodystrophy develops in a substantial number of patients during intermittent calcitriol therapy. Although declining serum PTH and alkaline phosphatase levels suggest the development of the adynamic lesion, bone formation decreases in some patients despite persistently high serum PTH levels. Calcitriol may directly suppress osteoblastic activity in patients with secondary hyperparathyroidism when given in large doses to patients undergoing peritoneal dialysis.

Hierarchical logistic regression models for imputation of unresolved enumeration status in undercount estimation

"In this article we describe a logistic regression modeling approach for nonresponse in the [U.S.] Post-Enumeration Survey (PES) that has desirable theoretical properties and that has performed well in practice.... In the 1990 PES, interviews were not obtained from approximately 1.2% of households in the sample, and approximately 2.1% of the individuals in interviewed households were considered unresolved after follow-up....The missing binary enumeration statuses for these unresolved cases were replaced with probabilities estimated under a statistical model that incorporated covariate information observed for these cases. This article describes an approach to modeling missing binary outcomes when there are a large number of covariates."

Predictors of long-term smoking cessation in head and neck cancer patients

Cigarette smoking is a major risk factor for head and neck cancer, and individuals who continue to smoke past diagnosis and treatment are at elevated risk for further disease. In a randomized controlled trial, a state of the art provider-delivered smoking cessation intervention was compared to a usual care advice control condition. The intervention consisted of surgeon- or dentist-delivered advice to stop smoking, a contracted quit date, tailored written materials, and booster advice sessions. Subjects were 186 patients with newly diagnosed first primary squamous cell carcinomas of the upper aerodigestive tract who had smoked cigarettes within the past year. At randomization, 88.2% of subjects were current smokers. At 12-month follow-up, 70.2% of subjects completing the trial (n = 114) were continuous abstainers; among baseline smokers alone the continuous abstinence (CA) rate was 64.6%. The cotinine validation rate at 12 months was 89.6%. Modeling techniques were utilized in order to derive expected CA rates, which included noncompleter subjects (n = 72). The CA rate expected at 1 year for the entire patient population was 64.2%, and for smokers alone the expected CA rate was 59.4%. Logistic regression analysis carried out on baseline smokers identified predictors of 12-month CA status. These included medical treatment, stage of change, age, nicotine dependence, and race. The intervention effect was not significant, although the sign of the effect was positive. Based on these findings, we recommend systematic brief advice to stop smoking for head and neck cancer patients, with a stepped care approach for patients less able to quit.

Epileptogenic effect of hypoxia in the immature rodent brain

The response to cerebral hypoxia/ischemia may be different in the neonate compared to other age groups. An in vivo model was developed in the rat to determine whether there are age-dependent differences in the effects of hypoxia on electroencephalographic (EEG) activity. EEG recordings were obtained from Long Evans hooded rats deprived of oxygen at five ages: postnatal days 5 to 7, 10 to 12, 15 to 17, 25 to 27, and 50 to 60. Oxygen concentration was varied from 0, 2, 3, and 4% between animals. EEGs were recorded in all animals before, during, and at 1 hour after exposure to the hypoxic condition and at 1 to 7 days afterward in a subset of animals. All animals were deprived of oxygen until the onset of apnea and bradycardia to 20 to 40% of baseline heart rate values. Hypoxia resulted in isoelectric EEG significantly more frequently in the animals deprived of oxygen at postnatal days 25 to 27 and 50 to 60 than in the younger age groups. A highly significant effect was that the animals deprived at postnatal days 5 to 17 revealed a high incidence of epileptiform EEG activity during hypoxia. In contrast, the older animals exhibited only rare isolated EEG spikes before reaching an isoelectric EEG. The severity of hypoxia-induced epileptiform EEG changes was highest in the animals subjected to moderately hypoxic conditions (3% and 4% oxygen) at postnatal days 10 to 12. Furthermore, epileptiform changes persisted for hours to days following prolonged episodes of hypoxia in the younger animals. This study demonstrates a unique response of the immature brain to exhibit epileptiform activity during hypoxia.