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Objective Childhood cancer survivors (CCS) face an increased risk of early cardiovascular disease (CVD). In our nationwide CCS cohort, we assessed the prevalence and determinants of dyslipidemia, a well-established risk factor for accelerated atherosclerosis and CVD. Methods Prevalence of dyslipidemia was cross-sectionally assessed in 2338 adult CCS and compared to adults with no cancer history (Lifelines, n = 132 226). Dyslipidemia was defined by multiple classifications as well as lipid abnormalities to investigate the impact on prevalence and determinants. Logistic regression models, adjusted for age, sex, and BMI, were used to assess the cohort effect on presence of dyslipidemia. Determinants of dyslipidemia were identified through multivariable logistic regression. Results CCS (median age 34.7 year, median follow-up 27.1 year) had significantly increased odds of dyslipidemia compared to the reference cohort according to all classifications (NCEP-ATP-III, WHO, EGIR, CTCAEv.4.03). In survivors without lipid-lowering agents (n = 2007), lipid abnormalities were present in 20.6% (triglycerides > 1.7 mmol/L), 30.3% (HDL-c < 1.0/1.3 mmol/L (male/female)), 29.9% (total cholesterol > 5.2 mmol/L), 7.3% (LDL-c > 4.1 mmol/L), and 7.7% (apolipoprotein-B > 130 mg/dL). Compared to references without lipid-lowering agents (n = 126 631), survivors had increased odds of high triglycerides (aOR = 1.89, 95% CI = 1.68-2.13), low HDL-c (aOR = 2.73, 95% CI = 2.46-3.03), and high apolipoprotein-B (aOR = 1.84, 95% CI = 1.53-2.20). Sex, age, BMI, physical activity, abdominal/pelvic, cranial, and total body irradiation, alkylating agents, smoking, growth hormone deficiency, and diabetes mellitus were associated with (≥1 definition of) dyslipidemia in CCS. Conclusions CCS is at increased risk of dyslipidemia, with various modifiable and non-modifiable determinants identified, underscoring the importance of survivor-specific risk assessment tools to control cardiovascular morbidity and mortality in this high-risk population. [ABSTRACT FROM AUTHOR]

Background: Childhood cancer survivors face high risks of adverse late health effects. Long‐term follow‐up care for childhood cancer survivors is crucial to improve their health and quality of life. However, implementation remains a challenge. To support implementation of high‐quality long‐term follow‐up care, we explored expected barriers and facilitators for establishing this follow‐up care among healthcare providers from four European clinics. Methods: A qualitative study was conducted using four focus groups comprising 30 healthcare providers in total. The semi‐structured interview guide was developed based on the Grol and Wensing framework. Data was analyzed following a thematic analysis, combining both inductive and deductive approaches to identify barriers and facilitators across the six levels of Grol and Wensing: innovation, professional, patient, social, organizational and economic and political. Results: Most barriers were identified on the organizational level, including insufficient staff, time, capacity and psychosocial support. Other main barriers included limited knowledge of late effects among healthcare providers outside the long‐term follow‐up care team, inability of some survivors to complete the survivor questionnaire and financial resources. Main facilitators included motivated healthcare providers and survivors, a skilled hospital team, collaborations with important stakeholders like general practitioners, and psychosocial care facilities, utilization of the international collaboration and reporting long‐term follow‐up care results to convince hospital managers. Conclusion: This study identified several factors for successful implementation of long‐term follow‐up care for childhood cancer survivors. Our findings showed that specific attention should be given to knowledge, capacity, and financial issues, along with addressing psychosocial issues of survivors. [ABSTRACT FROM AUTHOR]

Background: The objective of this study was to examine the prevalence of unhealthy lifestyle behaviors, overweight, and obesity in Dutch childhood cancer survivors (CCSs) compared with sibling controls and the Dutch general population. Other aims were to assess associated factors of unhealthy lifestyle behaviors, overweight, and obesity and to identify subgroups of CCSs at risk for these unhealthy statuses. Methods: The authors included 2253 CCSs and 906 siblings from the Dutch Childhood Cancer Survivor Study‐Late Effects After Childhood Cancer cohort, part 1, and added data from the Dutch general population. Questionnaire data were collected on overweight and obesity (body mass index >25.0 kg/m2), meeting physical activity guidelines (>150 minutes per week of moderate or vigorous exercises), excessive alcohol consumption (>14 and >21 alcoholic consumptions per week for women and men, respectively), daily smoking, and monthly drug use. Multivariable logistic regression analyses and two‐step cluster analyses were performed to examine sociodemographic‐related, health‐related, cancer‐related, and treatment‐related associated factors of unhealthy lifestyle behaviors and to identify subgroups of CCSs at risk for multiple unhealthy behaviors. Results: CCSs more often did not meet physical activity guidelines than their siblings (30.0% vs. 19.3%; p <.001). Married as marital status, lower education level, nonstudent status, and comorbidities were common associated factors for a body mass index ≥25.0 kg/m2 and insufficient physical activity, whereas male sex and lower education were shared associated factors for excessive alcohol consumption, daily smoking, and monthly drug use. A subgroup of CCSs was identified as excessive alcohol consumers, daily smokers, and monthly drug users. Conclusions: The current results emphasize the factors associated with unhealthy behaviors and the potential identification of CCSs who exhibit multiple unhealthy lifestyle behaviors. The results of this study indicate a higher prevalence of physical inactivity in childhood cancer survivors compared with sibling controls and the Dutch population, emphasizing the necessity for personalized health behavior interventions in childhood cancer survivors. These findings can be used in clinical practice to create awareness and to identify subgroups of childhood cancer survivors who need special attention regarding health behaviors. [ABSTRACT FROM AUTHOR]

Background: Dexamethasone is important in the treatment for pediatric acute lymphoblastic leukemia (ALL) but induces muscle atrophy with negative consequences for muscle mass, muscle strength, and functional abilities. The aim of this study was to establish the effect of a dexamethasone course on sarcopenia and physical frailty in children with ALL, and to explore prognostic factors. Methods: Patients with ALL aged 3–18 years were included during maintenance therapy. Patients had a sarcopenia/frailty assessment on the first day of (T1) and on the day after (T2) a 5‐day dexamethasone course. Sarcopenia was defined as low muscle strength in combination with low muscle mass. Prefrailty and frailty were defined as having two or ≥three of the following components, respectively: low muscle mass, low muscle strength, fatigue, slow walking speed, and low physical activity. Chi‐squared and paired t‐tests were used to assess differences between T1 and T2. Logistic regression models were estimated to explore patient‐ and therapy‐related prognostic factors for frailty on T2. Results: We included 105 patients, 61% were boys. Median age was 5.3 years (range: 3–18.8). At T1, sarcopenia, prefrailty, and frailty were observed in respectively 2.8%, 23.5%, and 4.2% of patients. At T2, the amount of patients with frailty had increased to 17.7% (p = 0.002), whereas the number of patients with sarcopenia and prefrailty remained similar. Higher ASMM (odds ratio [OR]: 0.49, 95% CI: 0.28–0.83), stronger handgrip strength (OR: 0.41, 95% CI: 0.22–0.77) and more physical activity minutes per day (OR: 0.98, 95% CI: 0.96–0.99) decreased the risk of frailty at T2. Slower walking performance (OR: 2, 95% CI: 1.2–3.39) increased the risk. Fatigue levels at T1 were not associated with frailty at T2. Conclusion: Physical frailty increased strikingly after a 5‐days dexamethasone course in children with ALL. Children with poor physical state at start of the dexamethasone course were more likely to be frail after the course. [ABSTRACT FROM AUTHOR]

Background: Overweight and obesity are common challenges among childhood cancer survivors. Overweight may be disguised, as survivors can have normal weight but high fat percentage (fat%) on dual-energy X-ray absorptiometry (DXA). We aimed to assess prevalence, identify determinants and biomarkers, and assess which method captures overweight best, in a nationwide cohort. Methods: The prevalence of overweight and obesity, primarily defined by body mass index (BMI), was assessed in the DCCSS-LATER cohort of adult survivors treated from 1963-2002, with the LifeLines cohort as reference. The associations between risk factors and overweight metrics were investigated using logistic regression. Additional overweight metrics included DXA fat%, waist circumference (WC), waist/hip ratio (WHR), waist/height ratio (WHtR), and high-molecular-weight (HMW) adiponectin. Results: A total of 2338 (mean age 35.5 years, follow-up 28.3 years) survivors participated. The overweight prevalence was 46.3% in men and 44.3% in women (obesity 11.2% and 15.9%, morbid obesity 2.4% and 5.4%), with highest rates among brain tumor survivors. Compared to controls, there was no overall increased overweight rate, but this was higher in women > 50 years, morbid obesity in men > 50 years. Overweight at cancer diagnosis (adjusted odds ratio [aOR] = 3.83, 95% CI 2.19-6.69), cranial radiotherapy (aOR = 3.21, 95% CI 1.99-5.18), and growth hormone deficiency (separate model, aOR = 1.61, 95% CI 1.00-2.59) were associated with overweight. Using BMI, WC, WHR, and WHtR, overweight prevalence was similar. Low HMW adiponectin, present in only 4.5% of survivors, was an insensitive overweight marker. Dual-energy X-ray absorptiometry–based classification identified overweight in an additional 30%, particularly after abdominal radiotherapy, total body irradiation, anthracyclines, and platinum. Conclusions: Overweight occurs in almost half of long-term survivors. There was no overall increased incidence of overweight compared to controls. We identified factors associated with overweight, as well as subgroups of survivors in whom DXA can more reliably assess overweight. [ABSTRACT FROM AUTHOR]

Background: Healthy behaviors, that is, engaging in regular physical activities, maintaining a healthy diet, limiting alcohol consumption, and avoiding tobacco and drug use, decrease the risk of developing late adverse health conditions in childhood cancer survivors. However, childhood cancer survivors may experience barriers to adopting and maintaining healthy behaviors. This study aimed to assess these barriers and facilitators to health behavior adoption and maintenance in childhood cancer survivors. Methods: A focus group (n = 12) and semi‐structured telephone interviews (n = 20) were conducted with a selected sample of European and Dutch childhood cancer survivors, respectively. The Theoretical Domains Framework (TDF) was used to inform the topic guide and analysis. Inductive thematic analysis was applied to identify categories relating to barriers and facilitators of health behavior adoption and maintenance, after which they were deductively mapped onto the TDF. Results: Ten TDF domains were identified in the data of which "Knowledge," "Beliefs about consequences," "Environmental context and resources," and "Social influences" were most commonly reported. Childhood cancer survivors expressed a need for knowledge on the importance of healthy behaviors, possibly provided by healthcare professionals. They indicated physical and long‐term benefits of healthy behaviors, available professional support, and a supporting and health‐consciously minded work and social environment to be facilitators. Barriers were mostly related to a lack of available time and an unhealthy environment. Lastly, (social) media was perceived as both a barrier and a facilitator to healthy behaviors. Conclusion: This study has identified education and available professional support in health behaviors and the relevance of healthy behaviors for childhood cancer survivors as key opportunities for stimulating health behavior adoption in childhood cancer survivors. Incorporating health behavior support and interventions for this population should therefore be a high priority. [ABSTRACT FROM AUTHOR]

Background: Childhood cancer survivors (CCSs) have an increased risk of developing chronic health conditions. Evidence suggests that poor health behaviors further increase health risks. Healthcare professionals (HCPs) involved in survivorship care have a key role in providing health behavior support (HBS) but can feel limited in their ability to do so. This study aims to explore European HCPs perceived facilitators and barriers to providing HBS to CCSs. Methods: Five focus groups with 30 HCPs from survivorship care clinics across Europe were conducted. Topic guides were informed by the Theoretical Domains Framework (TDF) to capture domains that may influence provision of HBS. Focus groups were analyzed with thematic analysis. Transcripts were inductively coded, after which axial coding was applied to organize codes into categories. Finally, categories were mapped onto the TDF domains. Results: Nine TDF domains were identified in the data. The most commonly reported TDF domains were "Knowledge", "Skills", and "Environmental context and resources". HCPs indicated that their lack of knowledge of the association between late effects and health behaviors, besides time restrictions, were barriers to HBS. Facilitators for HBS included possession of skills needed to pass on health behavior information, good clinic organization, and an established network of HCPs. Conclusions: This study identified education and training of HCPs as key opportunities to improve HBS. Survivorship care clinics should work towards establishing well‐integrated structured care with internal and external networks including HBS being part of routine care. Proper understanding of facilitators and barriers should lead to better survivorship care for CCSs. [ABSTRACT FROM AUTHOR]

Childhood cancer survivors (CCS) are at risk of kidney dysfunction. Recently, the shrunken pore syndrome (SPS) has been described, which is characterized by selectively impaired filtration of larger molecules like cystatin C, while filtration of smaller molecules like creatinine is unaltered. It has been associated with increased mortality, even in the presence of a normal estimated glomerular filtration rate (eGFR). The aim of this study was to evaluate the prevalence of SPS in CCS exposed to potentially nephrotoxic therapy. In the Dutch Childhood Cancer Survivor Study (DCCSS)-LATER 2 Renal study, a nationwide cross-sectional cohort study, 1024 CCS ≥5 years after diagnosis, aged ≥18 years at study, treated between 1963-2001 with nephrectomy, abdominal radiotherapy, total body irradiation, cisplatin, carboplatin, ifosfamide, high-dose cyclophosphamide or hematopoietic stem cell transplantation participated, and 500 age- and sex-matched controls form Lifelines. SPS was defined as an eGFRcys/eGFRcr ratio <0.6 in the absence of non-GFR determinants of cystatin C and creatinine metabolism (i.e. hyperthyroidism, corticosteroids, underweight). Three pairs of eGFR-equations were used; CKD-EPIcys/CKD-EPIcr, CAPA/LMR, and FAScys/FASage. Median age was 32 years. Although an eGFRcys/eGFRcr ratio <0.6 was more common in CCS (1.0%) than controls (0%) based on the CKD-EPI equations, most cases were explained by non-GFR determinants. The prevalence of SPS in CCS was 0.3% (CKD-EPI equations), 0.2% (CAPA/LMR) and 0.1% (FAS equations), and not increased compared to controls. CCS treated with nephrotoxic therapy are not at increased risk for SPS compared to controls. Yet, non-GFR determinants are more common and should be taken into account when estimating GFR. [ABSTRACT FROM AUTHOR]

A study conducted to find out the relation between circulating homocysteine and the risk of incident osteoporotic fracture is presented. According to the results, increased homocysteine level appears to be a strong and independent risk factor for osteoporotic fractures in older men and women.

Simple Summary: Survivors of childhood cancer have an increased risk to experience symptoms of severe and persistent fatigue. We studied how fatigue might affect the health-related quality of life of these survivors. Questionnaire items asking about a broad range of daily life aspects were compared between fatigued survivors, survivors without fatigue and the general Dutch population. A total of eleven aspects were studied which were all negatively affected by fatigue, with the largest impact seen for Vitality (how much energy does a person have), General Health (perception of current and future health) and Role Limitations (work-related activities). Results show the negative impact fatigue can have on the daily lives of survivors and why it is important to treat fatigue adequately. Background: Early detection and management of late effects of treatment and their impact on health-related quality of life (HRQOL) has become a key goal of childhood cancer survivorship care. One of the most prevalent late effects is chronic fatigue (CF). The current study aimed to investigate the association between CF and HRQOL in a nationwide cohort of CCS. Methods: Participants were included from the Dutch Childhood Cancer Survivor Study (DCCSS) LATER cohort, a nationwide cohort of CCS. Participants completed the Checklist Individual Strength (CIS) to indicate CF (CIS fatigue severity subscale ≥ 35 and duration of symptoms ≥6 months) and the Short Form-36 (SF-36) and TNO (Netherlands Organization for Applied Scientific Research) and AZL (Leiden University Medical Centre) Adult's Health-Related Quality of Life questionnaire (TAAQOL) as measures for HRQOL. Differences in mean HRQOL domain scores between CF and non-CF participants were investigated using independent samples t-tests and ANCOVA to adjust for age and sex. The association between CF and impaired HRQOL (scoring ≥ 2 SD below the population norm) was investigated using logistic regression analyses, adjusting for confounders. Results: A total of 1695 participants were included in the study. Mean HRQOL domain scores were significantly lower in participants with CF. In addition, CF was associated with impaired HRQOL on all of the domains (except physical functioning) with adjusted odds ratios ranging from 2.1 (95% CI 1.3–3.4; sexuality domain) to 30.4 (95% CI 16.4–56.2; vitality domain). Conclusions: CF is associated with impaired HRQOL, urging for the screening and regular monitoring of fatigue, and developing possible preventative programs and interventions. [ABSTRACT FROM AUTHOR]

Simple Summary: We studied survivors of childhood cancer who received cancer treatment that might affect the kidneys and compared them to controls from the general population. We investigated if there was a difference in the occurrence of tubular dysfunction. The tubules are the part of the kidney responsible for reabsorption of needed substances to the blood and the removal of wastes. After around 25 years since their cancer diagnosis, we found that in general there were no differences between survivors and controls, but survivors more often had losses of small proteins in the urine. Yet, some survivors of childhood cancer were found to have an increased risk of tubular dysfunction. Namely, survivors treated with the chemotherapeutic agents ifosfamide, cisplatin or carboplatin. Therefore, these patients should be monitored during their follow-up. The aim of this nationwide cross-sectional cohort study was to determine the prevalence of and risk factors for tubular dysfunction in childhood cancer survivors (CCS). In the DCCSS-LATER 2 Renal study, 1024 CCS (≥5 years after diagnosis), aged ≥ 18 years at study, treated between 1963 and 2001 with potentially nephrotoxic therapy (i.e., nephrectomy, abdominal radiotherapy, total body irradiation, cisplatin, carboplatin, ifosfamide, high-dose cyclophosphamide, or hematopoietic stem cell transplantation) participated, and 500 age- and sex-matched participants from Lifelines acted as controls. Tubular electrolyte loss was defined as low serum levels (magnesium < 0.7 mmol/L, phosphate < 0.7 mmol/L and potassium < 3.6 mmol/L) with increased renal excretion or supplementation. A α1-microglobulin:creatinine ratio > 1.7 mg/mmol was considered as low-molecular weight proteinuria (LMWP). Multivariable risk analyses were performed. After median 25.5 years follow-up, overall prevalence of electrolyte losses in CCS (magnesium 5.6%, potassium 4.5%, phosphate 5.5%) was not higher compared to controls. LMWP was more prevalent (CCS 20.1% versus controls 0.4%). LMWP and magnesium loss were associated with glomerular dysfunction. Ifosfamide was associated with potassium loss, phosphate loss (with cumulative dose > 42 g/m2) and LMWP. Cisplatin was associated with magnesium loss and a cumulative dose > 500 mg/m2 with potassium and phosphate loss. Carboplatin cumulative dose > 2800 mg/m2 was associated with potassium loss. In conclusion, long-term tubular dysfunction is infrequent. Yet, ifosfamide, cisplatin and carboplatin are risk factors. [ABSTRACT FROM AUTHOR]

Background: Fatigue is often reported by patients with childhood cancer both during and after cancer treatment. Several instruments to measure fatigue exist, although none are specifically validated for use in childhood cancer survivors (CCS). The aim of the current study was to present norm values and psychometric properties of the Checklist Individual Strength (CIS) and Short Fatigue Questionnaire (SFQ) in a nationwide cohort of CCS. Methods: In total, 2073 participants were included from the Dutch Childhood Cancer Survivor Study (DCCSS) LATER cohort. Normative data, construct validity, structural validity, and internal consistency were calculated for the CIS and SFQ. In addition, reliability and a cutoff score to indicate severe fatigue were determined for the SFQ. Results: Correlations between CIS/SFQ and vitality measures asking about fatigue were high (>0.8). Correlations between CIS/SFQ and measures of different constructs (sleep, depressive emotions, and role functioning emotional) were moderate (0.4-0.6). Confirmatory factor analysis resulted in a four-factor solution for the CIS and a one-factor solution for the SFQ with Cronbach's alpha for each (sub)scale showing good to excellent values (>0.8). Test-retest reliability of the SFQ was adequate (Pearson's correlation = 0.88; ICC = 0.946; weighted Cohen's kappa item scores ranged 0.31-0.50) and a cut-off score of 18 showed good sensitivity and specificity scores (92.6% and 91.3%, respectively). Conclusion: The current study shows that the SFQ is a good instrument to screen for severe fatigue in CCS. The CIS can be used as a tool to assess the multiple fatigue dimensions in CCS. [ABSTRACT FROM AUTHOR]

Objective: The objective was to predict insufficient response to 3 months methotrexate (MTX) in DMARD naïve rheumatoid arthritis patients. Methods: A Multivariable logistic regression model of rheumatoid arthritis patients starting MTX was developed in a derivation cohort with 285 patients starting MTX in a clinical multicentre, stratified single-blinded trial, performed in seven secondary care clinics and a tertiary care clinic. The model was validated in a validation cohort with 102 patients starting MTX at a tertiary care clinic. Outcome was insufficient response (disease activity score (DAS)28 >3.2) after 3 months of MTX treatment. Clinical characteristics, lifestyle variables, genetic and metabolic biomarkers were determined at baseline in both cohorts. These variables were dichotomized and used to construct a multivariable prediction model with backward logistic regression analysis. Results: The prediction model for insufficient response in the derivation cohort, included: DAS28>5.1, Health Assessment Questionnaire>0.6, current smoking, BMI>25 kg/m2, ABCB1 rs1045642 genotype, ABCC3 rs4793665 genotype, and erythrocyte-folate<750 nmol/L. In the derivation cohort, AUC of ROC curve was 0.80 (95%CI: 0.73–0.86), and 0.80 (95%CI: 0.69–0.91) in the validation cohort. Betas of the prediction model were transformed into total risk score (range 0–8). At cutoff of ≥4, probability for insufficient response was 44%. Sensitivity was 71%, specificity 72%, with positive and negative predictive value of 72% and 71%. Conclusions: A prognostics prediction model for insufficient response to MTX in 2 prospective RA cohorts by combining genetic, metabolic, clinical and lifestyle variables was developed and validated. This model satisfactorily identified RA patients with high risk of insufficient response to MTX. [ABSTRACT FROM AUTHOR]

Study Question: Are Inhibin B and testosterone levels reduced in boys with newly diagnosed cancer prior to therapy?Summary Answer: Pretreatment serum levels of Inhibin B and testosterone are significantly reduced in boys with newly diagnosed cancer, compared to reference values.What Is Already Known: Disease-related gonadal impairment has been demonstrated in girls and young women diagnosed with cancer, prior to therapy.Study Design, Size, Duration: We conducted a descriptive study in boys newly diagnosed with cancer between January 2006 and February 2014.Participants/materials, Setting, Methods: Serum Inhibin B and testosterone levels were determined in 224 boys, up to the age of 18 years, with newly diagnosed cancer prior to therapy. Hormone levels were compared with age-matched reference values. The cohort consisted of patients with acute lymphoblastic leukaemia (ALL), acute myeloid leukaemia (AML), Hodgkin lymphoma (HL), non-Hodgkin lym-phoma (NHL), nephroblastoma, neuroblastoma and sarcoma.Main Results and the Role Of Chance: This study demonstrates reduced serum levels of Inhibin B in boys with newly diagnosed cancer, compared to reference values (standard deviation score (SDS) -0.9, P < 0.001). Median Inhibin B level in patients was 103.5 ng/l (range 20-422). Of all patients, 78.6% showed Inhibin B levels below the 50th percentile, and 58.5% had Inhibin B levels below the 25th percentile. Serum testosterone levels were significantly lower than the reference range population (SDS -1.2, P < 0.001). Median testosterone level in pubertal patients was 7.3 nmol/l (range 0.1-23.6). No correlation with clinical signs of general illness and hormone levels were observed.Limitations, Reasons For Caution: In this study, reproductive hormone levels were compared with age-matched reference values. Future studies may compare reproductive hormone levels with case controls.Wider Implications Of the Findings: Future longitudinal studies are necessary to determine whether pretreatment impaired gonadal function at the time of cancer diagnosis is an important determinant of ultimate recovery of spermatogenesis after treatment and later on in adulthood.Study Funding/competing Interests: W.v.D. was supported by the Pediatric Oncology Center Society for Research (KOCR), Rotterdam, The Netherlands. A.-L.L.F.v.d.K. was supported by EU FP7 PanCare LIFE study. The authors have no conflicts of interest. [ABSTRACT FROM AUTHOR]

Background: Methotrexate (MTX) is an effective and safe drug in the treatment of juvenile idiopathic arthritis (JIA). Despite its safety, MTX-related gastrointestinal adverse effects before and after MTX administration, termed MTX intolerance, occur frequently, leading to non-compliance and potentially premature MTX termination. The aim of this study was to construct a risk model to predict MTX intolerance. Methods: In a prospective JIA cohort, clinical variables and single nucleotide polymorphisms were determined at MTX start. The Methotrexate Intolerance Severity Score was employed to measure MTX intolerance in the first year of treatment. MTX intolerance was most prevalent at 6 or 12 months after MTX start, which was defined as the outcome for the prediction model. The model was developed in 152 patients using multivariable logistic regression analysis and subsequently internally validated using bootstrapping. Results: The prediction model included the following predictors: JIA category, antinuclear antibody, parent/patient assessment of pain, Juvenile Arthritis Disease Activity Score-27, thrombocytes, alanine aminotransferase and creatinine. The model classified 77.5% of patients correctly, and 66.7% of patients after internal validation by bootstrapping. The lowest predicted risk of MTX intolerance was 18.9% and the highest predicted risk was 85.9%. The prediction model was transformed into a risk score (range 0-17). At a cut-off of ⩾6, sensitivity was 82.0%, specificity 56.1%, positive predictive value was 58.7% and negative predictive value 80.4%. Conclusions: This clinical prediction model showed moderate predictive power to detect MTX intolerance. To develop into a clinically usable tool, it should be validated in an independent cohort and updated with new predictors. Such an easy-to-use tool could then assist clinicians in identifying patients at risk to develop MTX intolerance, and in turn to monitor them closely and intervene timely in order to prevent the development of MTX intolerance. [ABSTRACT FROM AUTHOR]