Use of healthcare resources and drug expenditure before and after treatment of chronic hepatitis C with direct antiviral agents.

The aim of this study was to analyse the impact of treating chronic hepatitis C (CHC) with direct-acting agents (DAA) on the use of healthcare resources. We included all patients treated with DAA for CHC from January 2015 to December 2017 in Catalonia whose medical records from 12 months before to 24 months after treatment were available. Data were obtained from the Catalan Health Surveillance System. A total of 12,199 patients in Catalonia were treated with DAA for CHC. Of these, 11.3% had no-minimal fibrosis (F0-F1), 24.0% had moderate fibrosis (F2), 50.3% had significant fibrosis or cirrhosis (F3-F4), and 14.4% had decompensated cirrhosis. Use of healthcare resources decreased from the pre-treatment period to the post-treatment period for the following: hospital admissions due to complications of cirrhosis, from 0.19 to 0.12 per month per 100 patients (RR 0.57; 95% CI 0.47-0.68); length of hospital stay, from 12.9 to 12.2 days (RR 0.93; 95% CI 0.91-0.94); outpatient visits, from 65.0 to 49.2 (RR 0.75; 95% CI 0.74-0.75); and number of medication containers per patient per month, from 13.9 to 12.5 (RR 0.837; 95% CI 0.835-0.838). However, the number of invoices for antineoplastic treatment increased after DAA treatment, especially for patients with high morbidity or advanced fibrosis stage. In conclusion, a decrease in health resource use was seen in CHC patients treated with DAA, as measured by length of hospital stay, number of admissions due to cirrhosis complications, outpatient visits and overall drug invoicing. However, use of antineoplastic drugs increased significantly, especially in patients with cirrhosis and high morbidity.

Cognitive phenotypes 1 month after ICU discharge in mechanically ventilated patients: a prospective observational cohort study.

BACKGROUND: ICU patients undergoing invasive mechanical ventilation experience cognitive decline associated with their critical illness and its management. The early detection of different cognitive phenotypes might reveal the involvement of diverse pathophysiological mechanisms and help to clarify the role of the precipitating and predisposing factors. Our main objective is to identify cognitive phenotypes in critically ill survivors 1 month after ICU discharge using an unsupervised machine learning method, and to contrast them with the classical approach of cognitive impairment assessment. For descriptive purposes, precipitating and predisposing factors for cognitive impairment were explored. METHODS: A total of 156 mechanically ventilated critically ill patients from two medical/surgical ICUs were prospectively studied. Patients with previous cognitive impairment, neurological or psychiatric diagnosis were excluded. Clinical variables were registered during ICU stay, and 100 patients were cognitively assessed 1 month after ICU discharge. The unsupervised machine learning K-means clustering algorithm was applied to detect cognitive phenotypes. Exploratory analyses were used to study precipitating and predisposing factors for cognitive impairment. RESULTS: K-means testing identified three clusters (K) of patients with different cognitive phenotypes: K1 (n = 13), severe cognitive impairment in speed of processing (92%) and executive function (85%); K2 (n = 33), moderate-to-severe deficits in learning-memory (55%), memory retrieval (67%), speed of processing (36.4%) and executive function (33.3%); and K3 (n = 46), normal cognitive profile in 89% of patients. Using the classical approach, moderate-to-severe cognitive decline was recorded in 47% of patients, while the K-means method accurately classified 85.9%. The descriptive analysis showed significant differences in days (p = 0.016) and doses (p = 0.039) with opioid treatment in K1 vs. K2 and K3. In K2, there were more women, patients were older and had more comorbidities (p = 0.001) than in K1 or K3. Cognitive reserve was significantly (p = 0.001) higher in K3 than in K1 or K2. CONCLUSION: One month after ICU discharge, three groups of patients with different cognitive phenotypes were identified through an unsupervised machine learning method. This novel approach improved the classical classification of cognitive impairment in ICU survivors. In the exploratory analysis, gender, age and the level of cognitive reserve emerged as relevant predisposing factors for cognitive impairment in ICU patients. TRIAL REGISTRATION: ClinicalTrials.gov Identifier:NCT02390024; March 17,2015.

An assessment of existing models for individualized breast cancer risk estimation in a screening program in Spain.

BACKGROUND: The aim of this study was to evaluate the calibration and discriminatory power of three predictive models of breast cancer risk. METHODS: We included 13,760 women who were first-time participants in the Sabadell-Cerdanyola Breast Cancer Screening Program, in Catalonia, Spain. Projections of risk were obtained at three and five years for invasive cancer using the Gail, Chen and Barlow models. Incidence and mortality data were obtained from the Catalan registries. The calibration and discrimination of the models were assessed using the Hosmer-Lemeshow C statistic, the area under the receiver operating characteristic curve (AUC) and the Harrell's C statistic. RESULTS: The Gail and Chen models showed good calibration while the Barlow model overestimated the number of cases: the ratio between estimated and observed values at 5 years ranged from 0.86 to 1.55 for the first two models and from 1.82 to 3.44 for the Barlow model. The 5-year projection for the Chen and Barlow models had the highest discrimination, with an AUC around 0.58. The Harrell's C statistic showed very similar values in the 5-year projection for each of the models. Although they passed the calibration test, the Gail and Chen models overestimated the number of cases in some breast density categories. CONCLUSIONS: These models cannot be used as a measure of individual risk in early detection programs to customize screening strategies. The inclusion of longitudinal measures of breast density or other risk factors in joint models of survival and longitudinal data may be a step towards personalized early detection of BC.

Comparison of the consumption of antidepressants in the immigrant and native populations in a Spanish health region: an observational study.

BACKGROUND: Health professionals and organizations in developed countries adapt slowly to the increase of ethnically diverse populations attending health care centres. Several studies report that attention to immigrant mental health comes up with barriers in access, diagnosis and therapeutics, threatening equity. This study analyzes differences in exposure to antidepressant drugs between the immigrant and the native population of a Spanish health region. METHODS: Cross-sectional study of the dispensation of antidepressant drugs to the population aged 15 years or older attending the public primary health centres of a health region, 232,717 autochthonous and 33,361 immigrants, during 2008. Data were obtained from computerized medical records and pharmaceutical records of medications dispensed in pharmacies. Age, sex, country of origin, visits, date of entry in the regional health system, generic drugs and active ingredients were considered. Statistical analysis expressed the percentage of persons exposed to antidepressants stratified by age, gender, and country of origin and prevalence ratios of antidepressant exposition were calculated. RESULTS: Antidepressants were dispensed to 11% of native population and 2.6% of immigrants. Depending on age, native women were prescribed antidepressants between 1.9 and 2.7 times more than immigrant women, and native men 2.5 and 3.1 times more than their immigrant counterparts. Among immigrant females, the highest rate was found in the Latin Americans (6.6%) and the lowest in the sub-Saharans (1.4%). Among males, the highest use was also found in the Latin Americans (1.6%) and the lowest in the sub-Saharans (0.7%). The percentage of immigrants prescribed antidepressants increased significantly in relation to the number of years registered with the local health system. Significant differences were found for the new antidepressants, prescribed 8% more in the native population than in immigrants, both in men and in women. CONCLUSIONS: All the immigrants, regardless of the country of origin, had lower antidepressant consumption than the native population of the same age and sex. Latin American women presented the highest levels of consumption, and the sub-Saharan men the lowest. The prescription profiles also differed, since immigrants consumed more generics and fewer recently commercialized active ingredients.

[Observational study on drug spending in the immigrant and the indigenous population in the Lleida (Catalonia) health region]. / Estudio observacional del gasto farmacéutico en población inmigrante y autóctona de la región sanitaria de Lleida (Cataluña).

OBJECTIVE: To evaluate whether there are differences in drug spending between immigrant and Spanish-born populations and to assess whether drug consumption is associated with living environment (urban/rural). DESIGN: Observational cross-sectional study. SETTING: Lleida Health Region (LHR). PARTICIPANTS: 22,847 immigrants and 174,768 native born subjects, aged 15 to 64 years, residing in the LHR. MAIN MEASUREMENTS: Drug spending during the year 2007, demographical variables, region of origin and residence area (urban/rural). RESULTS: Native-born subjects spent more in all therapeutic drug groups than immigrants. In men, the relative risk ratio (RRR) of being in the highest quartile of expenditure was 3.2 (95% CI: 2.96-3.44) for native born versus immigrant and in women it was 2.1 (95% CI: 1.97-2.27). Immigrants from eastern Europe had the lowest risk of being in the highest quartile of expenditure, with statistically significant differences. Residents in the rural environment were more likely to have a higher pharmaceutical consumption than residents in the urban environment. CONCLUSION: Inequalities in drug spending were observed between immigrants and native born subjects. Further studies, either qualitative or mixed, should explore which factors are related to these differences and propose strategies addressed to reducing them.

Assessing sleep health in a European population: Results of the Catalan Health Survey 2015.

OBJECTIVE: To describe the overall sleep health of the Catalan population using data from the 2015 Catalan Health Survey and to compare the performance of two sleep health indicators: sleep duration and a 5-dimension sleep scale (SATED). METHODS: Multistage probability sampling representative of the non-institutionalized population aged 15 or more years, stratified by age, gender and municipality size, was used, excluding nightshift-workers. A total of 4385 surveys were included in the analyses. Associations between sleep health and the number of reported chronic diseases were assessed using non-parametric smoothed splines. Differences in the predictive ability of age-adjusted logistic regression models of self-rated health status were assessed. Multinomial logistic regression models were used to assess SATED determinants. RESULTS: Overall mean (SD) sleep duration was 7.18 (1.16) hours; and SATED score 7.91 (2.17) (range 0-10), lower (worse) scores were associated with increasing age and female sex. Alertness and efficiency were the most frequently impaired dimensions across age groups. SATED performed better than sleep duration when assessing self-rated health status (area under the curve = 0.856 vs. 0.798; p-value <0.001), and had a linear relationship with the number of reported chronic diseases, while the sleep duration relationship was u-shaped. CONCLUSIONS: Sleep health in Catalonia is associated with age and gender. SATED has some advantaged compared to sleep duration assessment, as it relates linearly to health indicators, has a stronger association with self-rated health status, and provides a more comprehensive assessment of sleep health. Therefore, the inclusion of multi-dimensional sleep health assessment tools in national surveys should be considered.

Outcomes of a randomized trial of hyperfractionated cranial radiation therapy for treatment of high-risk acute lymphoblastic leukemia: therapeutic efficacy and neurotoxicity.

PURPOSE: We evaluated 8-year survival and late neuropsychologic toxicity in children with acute lymphoblastic leukemia treated in a randomized clinical trial to test whether hyperfractionated (twice daily) cranial radiation therapy (CRT) can reduce incidence and severity of late toxicities associated with 18 Gy of CRT. PATIENTS AND METHODS: Between 1987 and 1995, 369 children treated on two consecutive Dana-Farber Cancer Institute Consortium protocols for high-risk acute lymphoblastic leukemia were randomly assigned to conventionally fractionated CRT (CFX) or hyperfractionated CRT (HFX) to a total dose of 18 Gy. Neuropsychologic testing was completed for 125 of 287 children in continuous complete remission. Event-free and overall survival, as well as neuropsychologic function, were compared for the two arms of the protocol. RESULTS: Eight-year event-free survival (+/- SE) was 80% +/- 3% for children randomly assigned to CFX and 72% +/- 3% for HFX (P =.06). Overall survival was 85% +/- 3% for CFX and 78% +/- 3% for HFX (P =.06). CNS relapses occurred in 2.8% of patients receiving CFX and 2.7% receiving HFX (P =.99). Cognitive function for both groups was solidly in the average range, with no group differences in intelligence, academic achievement, visuospatial reasoning, or verbal learning. Children on the HFX arm exhibited a modest advantage for visual memory (P <.05). CONCLUSION: HFX provides no benefit in terms of cognitive late effects and may compromise antileukemic efficacy. HFX should not be substituted for conventionally dosed CRT in children who require radiation therapy for treatment of acute lymphoblastic leukemia.

Height and weight in children treated for acute lymphoblastic leukemia: relationship to CNS treatment.

PURPOSE: We evaluated the long-term effects of treatment on height and weight in children with acute lymphoblastic leukemia (ALL) treated with one of the following three different CNS therapies: intrathecal therapy alone, intrathecal therapy with conventional cranial radiation, or intrathecal therapy with twice-daily radiation. PATIENTS AND METHODS: Between 1987 and 1995, 618 children treated on two consecutive Dana-Farber Cancer Institute Consortium protocols for ALL were measured for height and weight at diagnosis, and approximately every 6 months thereafter. Patient height, weight, and body mass index (BMI) were converted to z scores for age and sex using the 2000 Centers for Disease Control and Prevention growth charts for the United States. RESULTS: Children younger than 13 years at diagnosis had a statistically significant decrease in their height z scores and an increase in their BMI z scores, regardless of whether they had received cranial radiation. Young age at diagnosis and increased chemotherapy intensity were major risk factors. Unexpectedly, there was no significant difference in long-term height between children who received radiation and those who did not. CONCLUSION: Final height is compromised in survivors of ALL. The detrimental effects on height occur during therapy without the ability for long-term catch-up growth. Although patients became overweight for height, this seemed to be a result of relative height loss with normal weight gain rather than accelerated weight gain. The type of CNS treatment received did not affect changes in height, weight, or BMI.

Multidimensional independent predictors of cancer-related fatigue.

The purpose of this study was to identify independent predictors of clinically significant fatigue based upon a multidimensional model. A total of 180 cancer patients completed the Brief Fatigue Inventory (BFI), Functional Assessment of Cancer Therapy-Fatigue (FACT-F), Memorial Symptom Assessment Scale Short Form (MSAS-SF), and the Zung Self-Rating Depression Scale (SDS). Additional data included Karnofsky Performance Status (KPS) score, laboratory tests, and demographic information. The BFI usual fatigue severity > or =3/10 was defined as clinically significant fatigue. Possible independent variables were identified from a biopsychosocial model of fatigue. Fisher's exact test was used to univariately assess the association of each variable with clinically significant fatigue. Multiple logistic regression analyses were used to identify independent predictors of fatigue within each dimension, and then across dimensions. Fatigue was present in 113 (62%) patients, and 80 (44.4%) patients had usual fatigue > or =3/10. The unidimensional independent predictors were use of analgesics (situation dimension); hemoglobin and serum sodium (biomedical dimension); feeling drowsy, dyspnea, pain and lack of appetite (physical symptom dimension); and feeling sad and feeling irritable (psychological symptom dimension). In a multidimensional model, dyspnea, pain, lack of appetite, feeling drowsy, feeling sad, and feeling irritable predicted fatigue independently with good calibration (Hosmer Lemeshow Chi Square=5.73, P=0.68) and discrimination (area under the receiver operating characteristic curve=0.88). Physical and psychological symptoms predict fatigue independently in the multidimensional model, and superseded laboratory data. These findings support a symptom-oriented approach to assessment of cancer-related fatigue.

Trends in detection of invasive cancer and ductal carcinoma in situ at biennial screening mammography in Spain: a retrospective cohort study.

BACKGROUND: Breast cancer incidence has decreased in the last decade, while the incidence of ductal carcinoma in situ (DCIS) has increased substantially in the western world. The phenomenon has been attributed to the widespread adaption of screening mammography. The aim of the study was to evaluate the temporal trends in the rates of screen detected invasive cancers and DCIS, and to compare the observed trends with respect to hormone replacement therapy (HRT) use along the same study period. METHODS: Retrospective cohort study of 1,564,080 women aged 45-69 years who underwent 4,705,681 screening mammograms from 1992 to 2006. Age-adjusted rates of screen detected invasive cancer, DCIS, and HRT use were calculated for first and subsequent screenings. Poisson regression was used to evaluate the existence of a change-point in trend, and to estimate the adjusted trends in screen detected invasive breast cancer and DCIS over the study period. RESULTS: The rates of screen detected invasive cancer per 100.000 screened women were 394.0 at first screening, and 229.9 at subsequent screen. The rates of screen detected DCIS per 100.000 screened women were 66.8 at first screen and 43.9 at subsequent screens. No evidence of a change point in trend in the rates of DCIS and invasive cancers over the study period were found. Screen detected DCIS increased at a steady 2.5% per year (95% CI: 1.3; 3.8), while invasive cancers were stable. CONCLUSION: Despite the observed decrease in breast cancer incidence in the population, the rates of screen detected invasive cancer remained stable during the study period. The proportion of DCIS among screen detected breast malignancies increased from 13% to 17% throughout the study period. The rates of screen detected invasive cancer and DCIS were independent of the decreasing trend in HRT use observed among screened women after 2002.

[Current status of research in breast cancer screening in Spain: implications for prevention]. / Situación de la investigación en el cribado de cáncer de mama en España: implicaciones para la prevención.

OBJECTIVE: The consolidation of breast cancer screening programs, with full coverage of the target population in all Spanish regions, has encouraged the beginning of a joint research strategy. This strategy aims to improve the effectiveness of breast cancer screening by gathering information from distinct screening programs. METHODS: A retrospective cohort with information on over 1.5 million screened women was constructed to evaluate risk factors for a false-positive result. The impact of the change from digital mammography to screen-film mammography was evaluated, while results for interval cancers and false negatives are currently being studied. RESULTS: The results are highly useful from the perspective of public health, as they can be used to identify and improve the information provided to women with a higher risk of experiencing an adverse effect. These results will also be helpful to identify screening program-related characteristics and women's personal characteristics, which will allow better prevention strategies to be developed. CONCLUSIONS: The results obtained will be included in mathematical models currently under development to evaluate the efficiency of breast cancer screening. These models could be highly useful to provide information and guide clinical and health policy decisions on cancer prevention and control.

[Descriptive study of the use of emergency contraception in Catalonia (Spain). Comparison between a rural and an urban area]. / Estudio descriptivo sobre el uso de la anticoncepción de emergencia en Cataluña. Comparación entre una zona rural y una urbana.

OBJECTIVE: In the last few years, the number of unplanned pregnancies has increased, especially in young women. Among other measures, emergency contraception (EC) was introduced by the Health Department to reduce unwanted pregnancies. The aim of this study was to analyze EC use in Catalonia, and to compare a rural with an urban area (Lleida province and the metropolitan area of Barcelona). METHODS: We performed a descriptive study that included 17,149 women of fertile age who sought access to the EC pill between October 2004 and August 2007. Data were provided by the Maternal/Infant Health Program of the Public Health Department. RESULTS: EC was used primarily by women between 16 and 24 years of age, usually on the weekends. Most of these women (78.5%) had used EC twice and only 1.8% had used this medication once. Consumption was higher in Lleida, with a comparative utilization figure and 95% confidence interval of 1.42 (1.35-1.50) with respect to Barcelona. CONCLUSIONS: The finding that EC use was higher in younger women coincides with the goal of distributing this medication. EC seems not to be associated with a decrease in voluntary pregnancy terminations. More reproductive information is required from all the actors involved in policies and health interventions, encouraging healthier sexual behavior.

Genetic counseling program in familial breast cancer: analysis of its effectiveness, cost and cost-effectiveness ratio.

Women with a family history of breast cancer are at increased risk for developing this neoplasm. Starting surveillance more frequently at a younger age than the general population and the possibility of undergoing genetic testing are options for their medical management. We analyzed the benefits and costs of our clinical program in familial breast cancer (FBC) and carried out a cost-effectiveness analysis of such procedure. The benefits and costs of performing genetic counseling and a screening program in FBC based on 143 high-risk families registered in our database between June 1995 and December 2001 were analyzed. A decision tree was constructed to estimate the survival benefit and cost-effectiveness of the clinical genetic counseling program compared with the strategy of not performing any screening protocol. We estimated that the prevalence of a BRCA mutation in an unaffected relative of our high-risk cohort was 10% and that 53% of the mutations are found in the BRCA1 gene. We assigned a 58.5% lifetime risk of breast cancer for a 30-year-old mutation carrier according to the SEER data. The effectiveness of the screening was obtained from our experience and data for estimating survival were derived from other studies with longer follow-up. We used our local payment data to calculate the costs of the program. A mutation in the BRCA1 or BRCA2 genes was identified in 20% of the probands. Seventy primary breast cancer cases were recorded since the onset of the program. Thirty percent of the tumors were diagnosed through the screening program and 71% of them were lymph node-negative compared to 49% of the tumors diagnosed outside the program (p=0.1). The cost-effectiveness ratio of our FBC genetic counseling and screening program was 4,294 euros per life-year gained. The model was sensitive to the prevalence of mutation carriers, the lifetime risk of breast cancer and the effectiveness of the screening. In our setting and according to our model, this analysis suggests that a program of genetic testing and screening for breast cancer in a high-risk population may be cost-effective. These results need to be confirmed as more effective interventions for cancer prevention and screening are being implemented.

Central nervous system metastases in women who receive trastuzumab-based therapy for metastatic breast carcinoma.

BACKGROUND: Women with HER-2 overexpressing metastatic breast carcinoma benefit from trastuzumab-based therapy, but trastuzumab does not cross the blood-brain barrier. The authors characterized central nervous system (CNS) disease in these women. METHODS: Using pharmacy records, the authors retrospectively identified 153 women treated with trastuzumab alone or with chemotherapy for HER-2-positive metastatic breast carcinoma at Dana-Farber Partners Cancer Care from June 1998 to December 2000. A study cohort of 122 patients was identified after excluding patients without adequate clinical follow-up or who had CNS disease before trastuzumab treatment. Central nervous system disease was defined as one or more brain metastases or as leptomeningeal carcinomatosis. The median follow-up of this cohort was 23 months. RESULTS: Central nervous system metastases were identified in 34% of patients (95% confidence interval, 26-44%) at a median of 16 months after diagnosis of metastatic breast carcinoma and 6 months from the beginning of trastuzumab therapy. Ninety-three percent of patients with CNS disease presented with clinical symptoms. Five percent of patients with CNS disease had leptomeningeal involvement alone, although 14% had leptomeningeal involvement and parenchymal brain metastases. Fifty percent of patients were responding or had stable disease while receiving trastuzumab at other disease sites at the time of diagnosis of CNS metastasis. The median survival period after CNS metastases was 13 months. Fifty percent of patients died of progressive CNS disease. Patients receiving trastuzumab as first-line therapy for metastatic disease frequently developed brain metastases while responding to or stable on trastuzumab at other disease sites. CONCLUSIONS: Metastatic breast carcinoma to the CNS is common among patients receiving trastuzumab-based therapy, including patients responding to therapy outside the CNS. This may be due either to predilection for the CNS by HER-2-positive tumor cells and/or poor penetration of the CNS by trastuzumab or to improved visceral disease control leading to a longer life and onset of late tumor spread to the CNS. Efforts to characterize other risk factors for development of CNS disease, optimal screening algorithms, and new treatment strategies may be warranted.

Sequence analysis of clonal immunoglobulin and T-cell receptor gene rearrangements in children with acute lymphoblastic leukemia at diagnosis and at relapse: implications for pathogenesis and for the clinical utility of PCR-based methods of minimal residual disease detection.

Immunoglobulin (Ig) and T-cell receptor (TCR) gene rearrangements provide clonal markers useful for diagnosis and measurement of minimal residual disease (MRD) in acute lymphoblastic leukemia (ALL). We analyzed the sequences of Ig and TCR gene rearrangements obtained at presentation and relapse in 41 children with ALL to study clonal stability, which has important implications for monitoring MRD, during the course of the disease. In 42%, all original Ig and/or TCR sequences were conserved. In 24%, one original sequence was preserved but the other lost, and in 14% the original sequences were conserved with new sequences identified at relapse. In 20% only new sequences were found at relapse. Using primers designed from the novel relapse sequences, the relapse clone could be identified as subdominant clones in the diagnostic sample in 8 of 14 patients. Alteration of these clonal gene rearrangements is a common feature in childhood ALL. MRD detection should include multiple gene targets to minimize false-negative samples or include also multicolor flow cytometry. In some cases the leukemic progenitor cell might arise earlier in lineage before DHJH recombination but retain the capacity to further differentiate into cells capable of altering the pattern of Ig and/or TCR rearrangements.

Utilization of Ig heavy chain variable, diversity, and joining gene segments in children with B-lineage acute lymphoblastic leukemia: implications for the mechanisms of VDJ recombination and for pathogenesis.

Sequence analysis of the immunoglobulin heavy chain genes (IgH) has demonstrated preferential usage of specific variable (V), diversity (D), and joining (J) genes at different stages of B-cell development and in B-cell malignancies, and this has provided insight into B-cell maturation and selection. Knowledge of the association between rearrangement patterns based on updated databases and clinical characteristics of pediatric acute lymphoblastic leukemia (ALL) is limited. We analyzed 381 IgH sequences identified at presentation in 317 children with B-lineage ALL and assessed the V(H)D(H)J(H) gene utilization profiles. The D(H)J(H)-proximal V(H) segments and the D(H)2 gene family were significantly overrepresented. Only 21% of V(H)-J(H) joinings were potentially productive, a finding associated with a trend toward an increased risk of relapse. These results suggest that physical location at the V(H) locus is involved in preferential usage of D(H)J(H)-proximal V(H) segments whereas D(H) and J(H) segment usage is governed by position-independent molecular mechanisms. Molecular pathophysiology appears relevant to clinical outcome in patients who have only productive rearrangements, and specific rearrangement patterns are associated with differences in the tumor biology of childhood ALL.