Effective sample size: A measure of individual uncertainty in predictions.

Clinical prediction models are estimated using a sample of limited size from the target population, leading to uncertainty in predictions, even when the model is correctly specified. Generally, not all patient profiles are observed uniformly in model development. As a result, sampling uncertainty varies between individual patients' predictions. We aimed to develop an intuitive measure of individual prediction uncertainty. The variance of a patient's prediction can be equated to the variance of the sample mean outcome in n ∗ $$ {n}_{\ast } $$ hypothetical patients with the same predictor values. This hypothetical sample size n ∗ $$ {n}_{\ast } $$ can be interpreted as the number of similar patients n eff $$ {n}_{\mathrm{eff}} $$ that the prediction is effectively based on, given that the model is correct. For generalized linear models, we derived analytical expressions for the effective sample size. In addition, we illustrated the concept in patients with acute myocardial infarction. In model development, n eff $$ {n}_{\mathrm{eff}} $$ can be used to balance accuracy versus uncertainty of predictions. In a validation sample, the distribution of n eff $$ {n}_{\mathrm{eff}} $$ indicates which patients were more and less represented in the development data, and whether predictions might be too uncertain for some to be practically meaningful. In a clinical setting, the effective sample size may facilitate communication of uncertainty about predictions. We propose the effective sample size as a clinically interpretable measure of uncertainty in individual predictions. Its implications should be explored further for the development, validation and clinical implementation of prediction models.

Influence of initial misdiagnosis on mortality in patients with bacteraemia: propensity score matching and propensity score weighting analyses.

BACKGROUND: The diagnostic process is a key element of medicine but it is complex and prone to errors. Infectious diseases are one of the three categories of diseases in which diagnostic errors can be most harmful to patients. In this study we aimed to estimate the effect of initial misdiagnosis of the source of infection in patients with bacteraemia on 14 day mortality using propensity score methods to adjust for confounding. METHODS: Data from a previously described longitudinal cohort of patients diagnosed with monobacterial bloodstream infection (BSI) at the Leiden University Medical Centre (LUMC) between 2013 and 2015 were used. Propensity score matching and inversed probability of treatment weighting (IPTW) were applied to correct for confounding. The average treatment effect on the treated (ATT), which in this study was the average effect of initial misdiagnosis on the misdiagnosed (AEMM), was estimated. Methodological issues that were encountered when applying propensity score methods were addressed by performing additional sensitivity analyses. Sensitivity analyses consisted of varying caliper in propensity score matching and using different truncated weights in inversed probability of treatment weighting. RESULTS: Data of 887 patients were included in the study. Propensity scores ranged between 0.015 and 0.999 and 80 patients (9.9%) had a propensity score > 0.95. In the matched analyses, 35 of the 171 misdiagnosed patients died within 14 days (20.5%), versus 10 of the 171 correctly diagnosed patients (5.8%), yielding a difference of 14.6% (7.6%; 21.6%). In the total group of patients, the observed percentage of patients with an incorrect initial diagnosis that died within 14 days was 19.8% while propensity score reweighting estimated that their probability of dying would have been 6.5%, if they had been correctly diagnosed (difference 13.3% (95% CI 6.9%;19.6%)). After adjustment for all variables that showed disbalance in the propensity score a difference of 13.7% (7.4%; 19.9%) was estimated. Sensitivity analyses yielded similar results. However, performing weighted analyses without truncation yielded unstable results. CONCLUSION: Thus, we observed a substantial increase of 14 day mortality in initially misdiagnosed patients. Furthermore, several patients received propensity scores extremely close to one and were almost sure to be initially misdiagnosed.

Severity of haemolytic disease of the fetus and newborn in patients with a history of intrauterine transfusions in a previous pregnancy: A nationwide retrospective cohort study.

OBJECTIVE: Pregnant women who received at least one intrauterine transfusion (IUT) for haemolytic disease of the fetus and newborn (HDFN) in the preceding pregnancy are presumed to have a high likelihood of requiring IUTs again, often starting at an earlier gestational age. Our aim was to quantify these risks in a large national cohort. DESIGN: Retrospective cohort study of a nationwide Dutch database. SETTING: The Netherlands. POPULATION: All women treated in The Netherlands with IUTs for Rhesus D (RhD)- or Kell-mediated HDFN between 1999 and 2017 and their follow-up pregnancies were included. Pregnancies with an antigen-negative fetus were excluded. METHODS: Electronic patient files were searched for the number and gestational age of each IUT, and analysed using descriptive statistics and linear regression. MAIN OUTCOME MEASURES: Percentage of women requiring one or more IUTs again in the subsequent pregnancy, and gestational age at first IUT in both pregnancies. RESULTS: Of the 321 women in our study population, 21% (69) had a subsequent ongoing pregnancy at risk. IUTs were administered in 86% (59/69) of cases. In subsequent pregnancies, the median gestational age at first IUT was 3 weeks earlier (interquartile range -6.8 to 0.4) than in the preceding pregnancy. CONCLUSIONS: Our study shows that pregnant women with a history of IUTs in the previous pregnancy are highly likely to require IUTs again, and on average 3 weeks earlier. Clinicians need to be aware of these risks and ensure timely referral, and close surveillance from early pregnancy onwards. Additionally, for women with a history of IUT and their caregivers, this information is essential to enable adequate preconception counselling.

Vaginal misoprostol versus vaginal dinoprostone for cervical ripening and induction of labour: An individual participant data meta-analysis of randomised controlled trials.

BACKGROUND: Induction of labour (IOL) is common practice and different methods carry different effectiveness and safety profiles. OBJECTIVES: To compare the effectiveness, and maternal and perinatal safety outcomes of IOL with vaginal misoprostol versus vaginal dinoprostone using individual participant data from randomised clinical trials. SEARCH STRATEGY: The following databases were searched from inception to March 2023: CINAHL Plus, ClinicalTrials.gov, Cochrane Pregnancy and Childbirth Group Trial Register, Ovid Embase, Ovid Emcare, Ovid MEDLINE, Scopus and the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP). SELECTION CRITERIA: Randomised controlled trials (RCTs), with viable singleton gestation, no language restrictions, and all published and unpublished data. DATA COLLECTION AND ANALYSIS: An individual participant data meta-analysis was carried out. MAIN RESULTS: Ten of 52 eligible trials provided individual participant data, of which two were excluded after checking data integrity. The remaining eight trials compared low-dose vaginal misoprostol versus dinoprostone, including 4180 women undergoing IOL, which represents 32.8% of all participants in the published RCTs. Of these, 2077 were assigned to low-dose vaginal misoprostol and 2103 were assigned to vaginal dinoprostone. Compared with vaginal dinoprostone, low-dose vaginal misoprostol had a comparable rate of vaginal birth. Composite adverse perinatal outcomes did not differ between the groups. Compared with vaginal dinoprostone, composite adverse maternal outcomes were significantly lower with low-dose vaginal misoprostol (aOR 0.80, 95% CI 0.65-0.98, P = 0.03, I2 = 0%). CONCLUSIONS: Low-dose vaginal misoprostol and vaginal dinoprostone for IOL are comparable in terms of effectiveness and perinatal safety. However, low-dose vaginal misoprostol is likely to lead to a lower rate of composite adverse maternal outcomes than vaginal dinoprostone.

Conservative versus Liberal Oxygenation Targets in Intensive Care Unit Patients (ICONIC): A Randomized Clinical Trial.

Rationale: Supplemental oxygen is widely administered to ICU patients, but appropriate oxygenation targets remain unclear. Objectives: This study aimed to determine whether a low-oxygenation strategy would lower 28-day mortality compared with a high-oxygenation strategy. Methods: This randomized multicenter trial included mechanically ventilated ICU patients with an expected ventilation duration of at least 24 hours. Patients were randomized 1:1 to a low-oxygenation (PaO2, 55-80 mm Hg; or oxygen saturation as measured by pulse oximetry, 91-94%) or high-oxygenation (PaO2, 110-150 mm Hg; or oxygen saturation as measured by pulse oximetry, 96-100%) target until ICU discharge or 28 days after randomization, whichever came first. The primary outcome was 28-day mortality. The study was stopped prematurely because of the COVID-19 pandemic when 664 of the planned 1,512 patients were included. Measurements and Main Results: Between November 2018 and November 2021, a total of 664 patients were included in the trial: 335 in the low-oxygenation group and 329 in the high-oxygenation group. The median achieved PaO2 was 75 mm Hg (interquartile range, 70-84) and 115 mm Hg (interquartile range, 100-129) in the low- and high-oxygenation groups, respectively. At Day 28, 129 (38.5%) and 114 (34.7%) patients had died in the low- and high-oxygenation groups, respectively (risk ratio, 1.11; 95% confidence interval, 0.9-1.4; P = 0.30). At least one serious adverse event was reported in 12 (3.6%) and 17 (5.2%) patients in the low- and high-oxygenation groups, respectively. Conclusions: Among mechanically ventilated ICU patients with an expected mechanical ventilation duration of at least 24 hours, using a low-oxygenation strategy did not result in a reduction of 28-day mortality compared with a high-oxygenation strategy. Clinical trial registered with the National Trial Register and the International Clinical Trials Registry Platform (NTR7376).

Bacterial vaginosis in a subfertile population undergoing fertility treatments: a prospective cohort study.

PURPOSE: This study investigates the role of bacterial vaginosis (BV) on pregnancy rates during various fertility treatments. BV is known to influence several obstetric outcomes, such as preterm delivery and endometritis. Only few studies investigated the effect of BV in subfertile women, and studies found a negative effect on fecundity especially in the in vitro fertilisation population. METHODS: Observational prospective study, 76 couples attending a fertility clinic in the Netherlands between July 2019 and June 2022, undergoing a total of 133 attempts of intra uterine insemination, in vitro fertilization or intra cytoplasmatic sperm injection. Vaginal samples taken at oocyte retrieval or insemination were analysed on qPCR BV and 16S rRNA gene microbiota analysis of V1-V2 region. Logistic regression with a Generalized Estimated Equations analysis was used to account for multiple observations per couples. RESULTS: A total of 26% of the 133 samples tested positive for BV. No significant differences were observed in ongoing pregnancy or live birth rates based on BV status (OR 0.50 (0.16-1.59), aOR 0.32 (0.09-1.23)) or microbiome community state type. There was a tendency of more miscarriages based on positive BV status (OR 4.22 (1.10-16.21), aOR 4.28 (0.65-28.11)) or community state type group III and IV. On baseline qPCR positive participants had significantly higher body mass index and smoked more often. Odds ratios were adjusted for smoking status, body mass index, and socioeconomic status. CONCLUSION: Bacterial vaginosis does not significantly impact ongoing pregnancy rates but could affect miscarriage rates.

Testing on bacterial vaginosis in a subfertile population and time to pregnancy: a prospective cohort study.

PURPOSE: This study aimed to investigate the influence of bacterial vaginosis on time to pregnancy in subfertile couples. METHODS: Couples attending a teaching hospital in the Netherlands having an initial fertility assessment (IFA) between July 2019 and June 2022 were included in this prospective study, with follow-up of pregnancies until June 2023. Vaginal samples at IFA were analyzed on pH, qPCR BV, and 16S rRNA gene microbiome analysis of V1-V2 region. Main outcome measures were time from initial fertility assessment to ongoing pregnancy at 12 weeks and live birth, analyzed by Kaplan-Meier and Cox regression with adjustment for potential confounders. RESULTS: At IFA, 27% of 163 included participants tested positive for BV. BV status had no influence on time to ongoing pregnancy (HR 0.98, 0.60-1.61, aHR 0.97, 0.58-1.62). In persons with unexplained subfertility, positive BV status had a tendency of longer time to pregnancy. When persons had an indication for fertility treatment, positive BV status (HR 0.21, 0.05-0.88, aHR 0.19, 0.04-0.85) and microbiome community state type III and type IV had significant longer time to pregnancy. CONCLUSION: This study indicates that BV may have a potential negative impact on time to live birth pregnancy in subfertile persons with an indication for fertility treatment. This study did not find an association between BV and time to live birth pregnancy in a general group of subfertile couples or in unexplained subfertility. More research should be done in persons with unexplained subfertility and if treatment improves time to pregnancy.

Single-arm studies involving patient-reported outcome data in oncology: a literature review on current practice.

Patient-reported outcomes (PROs) are increasingly used in single-arm cancer studies. We reviewed 60 papers published between 2018 and 2021 of single-arm studies of cancer treatment with PRO data for current practice on design, analysis, reporting, and interpretation. We further examined the studies' handling of potential bias and how they informed decision making. Most studies (58; 97%) analysed PROs without stating a predefined research hypothesis. 13 (22%) of the 60 studies used a PRO as a primary or co-primary endpoint. Definitions of PRO objectives, study population, endpoints, and missing data strategies varied widely. 23 studies (38%) compared the PRO data with external information, most often by using a clinically important difference value; one study used a historical control group. Appropriateness of methods to handle missing data and intercurrent events (including death) were seldom discussed. Most studies (51; 85%) concluded that PRO results supported treatment. Conducting and reporting of PROs in cancer single-arm studies need standards and a critical discussion of statistical methods and possible biases. These findings will guide the Setting International Standards in Analysing Patient-Reported Outcomes and Quality of Life Data in Cancer Clinical Trials-Innovative Medicines Initiative (SISAQOL-IMI) in developing recommendations for the use of PRO-measures in single-arm studies.

Setting International Standards in Analyzing Patient-Reported Outcomes and Quality of Life Endpoints in Cancer Clinical Trials-Innovative Medicines Initiative (SISAQOL-IMI): stakeholder views, objectives, and procedures.

Patient-reported outcomes (PROs), such as symptoms, functioning, and other health-related quality-of-life concepts are gaining a more prominent role in the benefit-risk assessment of cancer therapies. However, varying ways of analysing, presenting, and interpreting PRO data could lead to erroneous and inconsistent decisions on the part of stakeholders, adversely affecting patient care and outcomes. The Setting International Standards in Analyzing Patient-Reported Outcomes and Quality of Life Endpoints in Cancer Clinical Trials-Innovative Medicines Initiative (SISAQOL-IMI) Consortium builds on the existing SISAQOL work to establish recommendations on design, analysis, presentation, and interpretation for PRO data in cancer clinical trials, with an expanded set of topics, including more in-depth recommendations for randomised controlled trials and single-arm studies, and for defining clinically meaningful change. This Policy Review presents international stakeholder views on the need for SISAQOL-IMI, the agreed on and prioritised set of PRO objectives, and a roadmap to ensure that international consensus recommendations are achieved.

Urinary Kidney Injury Biomarkers Are Associated with Ischemia-Reperfusion Injury Severity in Kidney Allograft Recipients.

BACKGROUND: We explored the potential of emerging and conventional urinary kidney injury biomarkers in recipients of living donor (LD) or donation after circulatory death (DCD) kidney transplantation, patients with chronic kidney disease (CKD), and individuals from the general population. METHODS: Urine samples from kidney allograft recipients with mild (LD; n = 199) or severe (DCD; n = 71) ischemia-reperfusion injury (IRI) were analyzed for neutrophil gelatinase-associated lipocalin (NGAL), insulin-like growth factor-binding protein 7 (IGFBP7), tissue inhibitor of metalloproteinases 2 (TIMP2), kidney injury molecule-1 (KIM-1), chemokine C-X-C motif (CXCL9), solute carrier family 22 member 2 (SLC22A2), nephrin, and uromodulin (UMOD) by quantitative multiplex LC-MS/MS analysis. The fold-change in biomarker levels was determined in mild and severe IRI and in patients with CKD stage 1-2 (n = 127) or stage ≥3 (n = 132) in comparison to the general population (n = 1438). Relationships between the biomarkers and total protein, ß2-microglobulin (B2M), creatinine, and osmolality were assessed. RESULTS: NGAL, IGFBP7, TIMP2, KIM-1, CXCL9, and UMOD were quantifiable, whereas nephrin and SLC22A2 were below the limit of detection. Kidney injury biomarkers were increased up to 6.2-fold in allograft recipients with mild IRI and 8.3-fold in recipients with severe IRI, compared to the reference population, with the strongest response observed for NGAL and B2M. In CKD stage 1-2, B2M, NGAL, IGFBP7, TIMP2, KIM-1, UMOD, and CXCL9 were not altered, but in individuals with CKD stage ≥3, B2M, NGAL, and KIM-1 were increased up to 1.3-fold. IGFBP7, TIMP2, NGAL, and CXCL9 were strongly correlated (all r ≥ 0.8); correlations with B2M and TP were smaller (all r ≤ 0.6). CONCLUSIONS: IRI, but not stable CKD, was associated with increased urinary levels of kidney injury biomarkers determined by LC-MS/MS. Absolute and multiplexed protein quantitation by LC-MS/MS is an effective strategy for biomarker panel evaluation for translation toward the clinical laboratory.

Serum Potassium and Risk of Death or Kidney Replacement Therapy in Older People With CKD Stages 4-5: Eight-Year Follow-up.

RATIONALE & OBJECTIVE: Hypokalemia may accelerate kidney function decline. Both hypo- and hyperkalemia can cause sudden cardiac death. However, little is known about the relationship between serum potassium and death or the occurrence of kidney failure requiring replacement therapy (KRT). We investigated this relationship in older people with chronic kidney disease (CKD) stage 4-5. STUDY DESIGN: Prospective observational cohort study. SETTING & PARTICIPANTS: We followed 1,714 patients (≥65 years old) from the European Quality (EQUAL) study for 8 years from their first estimated glomerular filtration rate (eGFR)<20mL/min/1.73m2 measurement. EXPOSURE: Serum potassium was measured every 3 to 6 months and categorized as≤3.5,>3.5-≤4.0,>4.0-≤4.5,>4.5-≤5.0 (reference),>5.0-≤5.5, >5.5-≤6.0, and>6.0mmol/L. OUTCOME: The combined outcome death before KRT or start of KRT. ANALYTICAL APPROACH: The association between categorical and continuous time-varying potassium and death or KRT start was examined using Cox proportional hazards and restricted cubic spline analyses, adjusted for age, sex, diabetes, cardiovascular disease, renin-angiotensin-aldosterone system (RAAS) inhibition, eGFR, and subjective global assessment (SGA). RESULTS: At baseline, 66% of participants were men, 42% had diabetes, 47% cardiovascular disease, and 54% used RAAS inhibitors. Their mean age was 76±7 (SD) years, mean eGFR was 17±5 (SD) mL/min/1.73m2, and mean SGA was 6.0±1.0 (SD). Over 8 years, 414 (24%) died before starting KRT, and 595 (35%) started KRT. Adjusted hazard ratios for death or KRT according to the potassium categories were 1.6 (95% CI, 1.1-2.3), 1.4 (95% CI, 1.1-1.7), 1.1 (95% CI, 1.0-1.4), 1 (reference), 1.1 (95% CI, 0.9-1.4), 1.8 (95% CI, 1.4-2.3), and 2.2 (95% CI, 1.5-3.3). Hazard ratios were lowest at a potassium of about 4.9mmol/L. LIMITATIONS: Shorter intervals between potassium measurements would have allowed for more precise estimations. CONCLUSIONS: We observed a U-shaped relationship between serum potassium and death or KRT start among patients with incident CKD 4-5, with a nadir risk at a potassium level of 4.9mmol/L. These findings underscore the potential importance of preventing both high and low potassium in patients with CKD 4-5. PLAIN-LANGUAGE SUMMARY: Abnormal potassium blood levels may increase the risk of death or kidney function decline, especially in older people with chronic kidney disease (CKD). We studied 1,714 patients aged≥65 years with advanced CKD from the European Quality (EQUAL) study and followed them for 8 years. We found that both low and high levels of potassium were associated with an increased risk of death or start of kidney replacement therapy, with the lowest risk observed at a potassium level of 4.9 mmol/L. In patients with CKD, the focus is often on preventing high blood potassium. However, this relatively high optimum potassium level stresses the potential importance of also preventing low potassium levels in older patients with advanced CKD.

Metabolomics dissection of depression heterogeneity and related cardiometabolic risk.

BACKGROUND: A recent hypothesis postulates the existence of an 'immune-metabolic depression' (IMD) dimension characterized by metabolic dysregulations. Combining data on metabolomics and depressive symptoms, we aimed to identify depressions associated with an increased risk of adverse metabolic alterations. METHOD: Clustering data were from 1094 individuals with major depressive disorder in the last 6 months and measures of 149 metabolites from a 1H-NMR platform and 30 depressive symptoms (IDS-SR30). Canonical correlation analyses (CCA) were used to identify main independent metabolite-symptom axes of variance. Then, for the replication, we examined the association of the identified dimensions with metabolites from the same platform and cardiometabolic diseases in an independent population-based cohort (n = 6572). RESULTS: CCA identified an overall depression dimension and a dimension resembling IMD, in which symptoms such as sleeping too much, increased appetite, and low energy level had higher relative loading. In the independent sample, the overall depression dimension was associated with lower cardiometabolic risk, such as (i.e. per s.d.) HOMA-1B -0.06 (95% CI -0.09 - -0.04), and visceral adipose tissue -0.10 cm2 (95% CI -0.14 - -0.07). In contrast, the IMD dimension was associated with well-known cardiometabolic diseases such as higher visceral adipose tissue 0.08 cm2 (95% CI 0.04-0.12), HOMA-1B 0.06 (95% CI 0.04-0.09), and lower HDL-cholesterol levels -0.03 mmol/L (95% CI -0.05 - -0.01). CONCLUSIONS: Combining metabolomics and clinical symptoms we identified a replicable depression dimension associated with adverse metabolic alterations, in line with the IMD hypothesis. Patients with IMD may be at higher cardiometabolic risk and may benefit from specific treatment targeting underlying metabolic dysregulations.

The association between adiposity and atypical energy-related symptoms of depression: A role for metabolic dysregulations.

BACKGROUND: Adiposity has been shown to be linked with atypical energy-related symptoms (AES) of depression. We used genomics to separate the effect of adiposity from that of metabolic dysregulations to examine whether the link between obesity and AES is dependent on the presence of metabolic dysregulations. METHOD: Data were from NEO (n = 5734 individuals) and NESDA (n = 2238 individuals) cohorts, in which the Inventory of Depressive Symptomatology (IDS-SR30) was assessed. AES profile was based on four symptoms: increased appetite, increased weight, low energy level, and leaden paralysis. We estimated associations between AES and two genetic risk scores (GRS) indexing increasing total body fat with (metabolically unhealthy adiposity, GRS-MUA) and without (metabolically healthy adiposity, GRS-MHA) metabolic dysregulations. RESULTS: We validated that both GRS-MUA and GRS-MHA were associated with higher total body fat in NEO study, but divergently associated with biomarkers of metabolic health (e.g., fasting glucose and HDL-cholesterol) in both cohorts. In the pooled results, per standard deviation, GRS-MUA was specifically associated with a higher AES score (ß = 0.03, 95%CI: 0.01; 0.05), while there was no association between GRS-MHA and AES (ß = -0.01, 95%CI: -0.03; 0.01). CONCLUSION: These results suggest that the established link between adiposity and AES profile emerges in the presence of metabolic dysregulations, which may represent the connecting substrate between the two conditions.

Effect of residual kidney function and dialysis adequacy on chronic pruritus in dialysis patients.

BACKGROUND: Chronic kidney disease-associated pruritus (CKD-aP) is common in dialysis patients, and is associated with lower quality of life and increased risk of death. We investigated the association between residual estimated glomerular filtration rate (eGFR), dialysis adequacy or serum phosphate level and CKD-aP in incident dialysis patients. METHODS: A total of 1256 incident hemodialysis (HD) and 670 peritoneal dialysis (PD) patients (>18 years) from the Netherlands Cooperative Study on the Adequacy of Dialysis (NECOSAD) study were included (1997-2007) and followed until death, transplantation or a maximum of 10 years. CKD-aP was measured using a single item of the Kidney Disease Quality of Life Instrument-36. The associations were studied by logistic and linear regression analyses, adjusted for potential baseline confounders. RESULTS: At baseline mean (standard deviation) age was 60 (16) years, 62% were men and median (interquartile range) residual eGFR was 3.4 (1.7; 5.3) mL/min/1.73 m2. The prevalence of CKD-aP (∼70%) was similar in HD and PD. It was observed that 12 months after starting dialysis (after multivariable adjustment) each 1 mL/min/1.73 m2 higher residual eGFR, one unit higher total weekly Kt/V, or 1 mmol/L lower serum phosphate level was associated with lower burden of CKD-aP in HD and PD patients of -0.05 (95% CI -0.09; -0.02) and -0.09 (95% CI -0.13; -0.05), -0.15 (95% CI -0.26; -0.05) and -0.35 (95% CI -0.54; -0.16), and of -0.34 (95%CI: -0.51; -0.17) and -0.45 (95%CI: -0.71; -0.19), respectively. We found no association between dialysis Kt/V and CKD-aP. CONCLUSIONS: Higher residual eGFR and lower serum phosphate level, but not the dialysis dose, were related with lower burden of CKD-aP in dialysis patients.

A Bayesian (meta-)regression model for treatment effects on the risk difference scale.

In clinical settings, the absolute risk reduction due to treatment that can be expected in a particular patient is of key interest. However, logistic regression, the default regression model for trials with a binary outcome, produces estimates of the effect of treatment measured as a difference in log odds. We explored options to estimate treatment effects directly as a difference in risk, specifically in the network meta-analysis setting. We propose a novel Bayesian (meta-)regression model for binary outcomes on the additive risk scale. The model allows treatment effects, covariate effects, interactions and variance parameters to be estimated directly on the linear scale of clinical interest. We compared effect estimates from this model to (1) a previously proposed additive risk model by Warn, Thompson and Spiegelhalter ("WTS model") and (2) backtransforming the predictions from a logistic model to the natural scale after regression. The models were compared in a network meta-analysis of 20 hepatitis C trials, as well as in the analysis of simulated single trial settings. The resulting estimates diverged, in particular for small sample sizes or true risks close to 0% or 100%. Researchers should be aware that modelling untransformed risk can yield very different results from default logistic models. The treatment effect in participants with such extreme predicted risks weighed more heavily on the overall treatment effect estimate from our proposed model compared to the WTS model. In our network meta-analysis, this sensitivity of our proposed model was needed to detect all information in the data.

Both perimenstrual and nonperimenstrual migraine days respond to anti-calcitonin gene-related peptide (receptor) antibodies.

BACKGROUND AND PURPOSE: Anti-calcitonin gene-related peptide (CGRP) (receptor) antibodies effectively reduce overall migraine attack frequency, but whether there are differences in effect between perimenstrual and nonperimenstrual migraine days has not been investigated. METHODS: We performed a single-arm study among women with migraine. Participants were followed with electronic E-diaries during one (pretreatment) baseline month and 6 months of treatment with either erenumab or fremanezumab. Differences in treatment effect on perimenstrual and nonperimenstrual migraine days were assessed using a mixed effects logistic regression model, with migraine day as dependent variable; treatment, menstrual window, and an interaction term (treatment × menstrual window) as fixed effects; and patient as a random effect. RESULTS: There was no interaction between the menstrual window and treatment effect, indicating that the reduction in migraine days under treatment was similar during the menstrual window and the remainder of the menstrual cycle (odds ratio for treatment = 0.44, 95% confidence interval = 0.38-0.51). CONCLUSIONS: Our findings support prophylactic use of anti-CGRP (receptor) antibodies for women with menstrual migraine, as this leads to consistent reductions in number of migraine days during the entire menstrual cycle.

Sex differences in migraine attack characteristics: A longitudinal E-diary study.

OBJECTIVE: In this prospective cohort study, characteristics of perimenstrual and non-perimenstrual migraine attacks in women were compared with migraine attacks in men. BACKGROUND: Women report longer migraine attacks and more accompanying symptoms than men in cross-sectional questionnaire studies, but this has not been confirmed in longitudinal studies. Supposed differences could result from different characteristics specific to perimenstrual migraine attacks, or of attacks in women in general. METHODS: This cohort study was performed among patients with migraine who were treated at the Leiden Headache Clinic. We assessed differences in migraine attack characteristics between men and women who were prospectively followed by a previously validated electronic headache diary. The primary outcome was "attack" duration. Differences between perimenstrual (Days -2 to +3 of the menstrual cycle) and non-perimenstrual attacks in women versus attacks in men were corrected for age, chronic migraine, and medication overuse headache. RESULTS: A total of 1347 women and 284 men were included, reflecting the preponderance of women in migraine prevalence. Crude median (first and third quartile [Q1-Q3]) attack duration in men was 32.1 [17.7-53.6] h, compared to 36.7 [21.9-62.4] h for non-perimenstrual migraine attacks and 44.4 [17.9-79.0] h for perimenstrual migraine attacks in women. After correction for confounding, perimenstrual migraine attacks were 1.62 (95% confidence interval [CI] 1.47-1.79; p < 0.001) and non-perimenstrual 1.15 (95% CI 1.05-1.25; p = 0.003) times longer compared to migraine attacks in men. The mean relapse percentage in men was 9.2%, compared to 12.6% for non-perimenstrual migraine attacks, and 15.7% for perimenstrual migraine attacks. Relapse risk was greater for perimenstrual (odds ratio [OR] 2.39, 95% CI 1.93-2.95; p < 0.001), but not for non-perimenstrual (OR 1.18, 95% CI 0.97-1.45; p = 0.060) attacks. Migraine attacks in women were more often accompanied by photophobia, phonophobia, and nausea, but less often aura. CONCLUSION: Compared to attacks in men, both perimenstrual and non-perimenstrual migraine attacks are of longer duration and are more often accompanied by associated symptoms. A sex-specific approach to migraine treatment and research is needed.

Tying research question and analytical strategy when variables are affected by medication use.

Ill-defined research questions could be particularly problematic in an epidemiological setting where measurements fluctuate over time due to intercurrent events, such as medication use. When a research question fails to specify how medication use should be handled methodologically, arbitrary decisions may be made during the analysis phase, which likely leads to a mismatch between the intended question and the performed analysis. The mismatch can result in vastly different or meaningless interpretations of estimated effects. Thus, a research question such as "what is the effect of X on Y?" requires further elaboration, and it should consider whether and how medication use has affected the measurements of interest. In our study, we will discuss how well-defined questions can be formulated when medication use is involved in observational studies. We will distinguish between a situation where an exposure is affected by medication use and where the outcome of interest is affected by medication use. For each setting, we will give examples of different research questions that could be asked depending on how medication use is considered in the estimand and discuss methodological considerations under each question.

Somatic growth in single ventricle patients: A systematic review and meta-analysis.

AIM: To map somatic growth patterns throughout Fontan palliation and summarise evidence on its key modifiers. METHODS: Databases were searched for relevant articles published from January 2000 to December 2021. Height and weight z scores at each time point (birth, Glenn procedure, Fontan procedure and >5 years after Fontan completion) were pooled using a random effects meta-analysis. A random effects meta-regression model was fitted to model the trend in z scores over time. RESULTS: Nineteen studies fulfilled eligibility criteria, yielding a total of 2006 participants. The z scores for height and weight were markedly reduced from birth to the interstage period, but recovered by about 50% following the Glenn procedure. At >10 years after the Fontan procedure, the z scores for weight seemed to normalise despite persistent lower height, resulting in increased body mass index. The review revealed a number of modifiers of somatic growth, including aggressive nutritional management, timing of Glenn/Fontan, prompt resolution of complications and obesity prevention programmes in adolescence and adulthood. CONCLUSION: This review mapped the somatic growth of single ventricle patients and summarised key modifiers that may be amendable to improvement. These data provide guidance on strategies to further optimise somatic growth in this population and may serve as a benchmark for clinical follow-up.

Evaluation of the Value of Waist Circumference and Metabolomics in the Estimation of Visceral Adipose Tissue.

Visceral adipose tissue (VAT) is a strong prognostic factor for cardiovascular disease and a potential target for cardiovascular risk stratification. Because VAT is difficult to measure in clinical practice, we estimated prediction models with predictors routinely measured in general practice and VAT as outcome using ridge regression in 2,501 middle-aged participants from the Netherlands Epidemiology of Obesity study, 2008-2012. Adding waist circumference and other anthropometric measurements on top of the routinely measured variables improved the optimism-adjusted R2 from 0.50 to 0.58 with a decrease in the root-mean-square error (RMSE) from 45.6 to 41.5 cm2 and with overall good calibration. Further addition of predominantly lipoprotein-related metabolites from the Nightingale platform did not improve the optimism-corrected R2 and RMSE. The models were externally validated in 370 participants from the Prospective Investigation of Vasculature in Uppsala Seniors (PIVUS, 2006-2009) and 1,901 participants from the Multi-Ethnic Study of Atherosclerosis (MESA, 2000-2007). Performance was comparable to the development setting in PIVUS (R2 = 0.63, RMSE = 42.4 cm2, calibration slope = 0.94) but lower in MESA (R2 = 0.44, RMSE = 60.7 cm2, calibration slope = 0.75). Our findings indicate that the estimation of VAT with routine clinical measurements can be substantially improved by incorporating waist circumference but not by metabolite measurements.