Inconsistency in ferritin reference intervals across laboratories: a major concern for clinical decision making.

Objectives: Iron deficiency anemia is a significant global health concern, diagnosed by measuring hemoglobin concentrations in combination with plasma ferritin concentration. This study investigated the variability in ferritin reference intervals among laboratories in the Netherlands and examined how this affects the identification of iron-related disorders.

Methods: Ferritin reference intervals from 52 Dutch ISO15189-certified medical laboratories were collected.

Age-Specific Reference Intervals for Thyroid-Stimulating Hormones and Free Thyroxine to Optimize Diagnosis of Thyroid Disease.

Thyroid-stimulating hormone (TSH) and subsequent free thyroxine (FT4) concentrations outside the reference interval (RI) are used to diagnose thyroid diseases. Most laboratories do not provide age-specific RIs for TSH and FT4 beyond childhood, although TSH concentrations vary with age. Therefore, we aimed to establish TSH and FT4 age-specific RIs throughout life and aimed to determine whether using these RIs would result in reclassification of thyroid disease diagnoses in adults.

Troponin testing in routine primary care: observations from a dynamic cohort study in the Amsterdam metropolitan area.

Objectives: Troponin testing is indicated in the diagnostic work-up of acute coronary syndrome (ACS) and incorporated in risk stratification pathways. This study aims to gain insights on the use, outcomes, and diagnostic accuracy of troponin testing in routine primary care; a setting that is understudied.

Methods: Routine data were used from the academic primary care network in the Amsterdam metropolitan area (968,433 patient records).

Should we depend on reference intervals from manufacturer package inserts? Comparing TSH and FT4 reference intervals from four manufacturers with results from modern indirect methods and the direct method.

Objectives: Correct interpretation of thyroid function tests relies on correct reference intervals (RIs) for thyroid-stimulating hormone (TSH) and free thyroxine (FT4). ISO15189 mandates periodic verification of RIs, but laboratories struggle with cost-effective approaches. We investigated whether indirect methods (utilizing historical laboratory data) could replace the direct approach (utilizing healthy reference individuals) and compared results with manufacturer-provided RIs for TSH and FT4.

The impact of the COVID-19 pandemic on Positive Health among older adults in relation to the complexity of health problems.

Background: The broad concept of health as "the ability to adapt and self-manage in the face of social, physical and emotional challenges" has been operationalized by "Positive Health," a framework increasingly used in the Netherlands. We explored to what degree the impact of the COVID-19 pandemic and preventive measures on Positive Health differed between community-dwelling older adults without, with mild and with complex health problems, as well as differences flowing from their use of preventive measures.

Methods: During the second wave in the Netherlands (November 2020-February 2021), a convenience sample of adults aged ≥65 years completed an online questionnaire.

Incidence and Determinants of Spontaneous Normalization of Subclinical Hypothyroidism in Older Adults.

Context: With age, the prevalence of subclinical hypothyroidism rises. However, incidence and determinants of spontaneous normalization remain largely unknown.

Objective: To investigate incidence and determinants of spontaneous normalization of TSH levels in older adults with subclinical hypothyroidism.

Optimizing the Dutch newborn screening for congenital hypothyroidism by incorporating amino acids and acylcarnitines in a machine learning-based model.

Objective: Congenital hypothyroidism (CH) is an inborn thyroid hormone (TH) deficiency mostly caused by thyroidal (primary CH) or hypothalamic/pituitary (central CH) disturbances. Most CH newborn screening (NBS) programs are thyroid-stimulating-hormone (TSH) based, thereby only detecting primary CH. The Dutch NBS is based on measuring total thyroxine (T4) from dried blood spots, aiming to detect primary and central CH at the cost of more false-positive referrals (FPRs) (positive predictive value (PPV) of 21% in 2007-2017).

The effect of hormonal contraceptive therapy on clinical laboratory parameters: a literature review.

Hormonal contraceptives (HC) are widely used among women in reproductive ages. In this review, the effects of HCs on 91 routine chemistry tests, metabolic tests, and tests for liver function, hemostatic system, renal function, hormones, vitamins and minerals were evaluated. Test parameters were differently affected by the dosage, duration, composition of HCs and route of administration.

Harmonization of indirect reference intervals calculation by the Bhattacharya method.

Objectives: The aim of this study was to harmonize the criteria for the Bhattacharya indirect method Microsoft Excel Spreadsheet for reference intervals calculation to reduce between-user variability and use these criteria to calculate and evaluate reference intervals for eight analytes in two different years.

Methods: Anonymized laboratory test results from outpatients were extracted from January 1st 2018 to December 31st 2019. To assure data quality, we examined the monthly results from an external quality control program.

Moving average quality control of routine chemistry and hematology parameters - a toolbox for implementation.

Objectives: Moving average quality control (MA QC) is a patient-based real-time quality control system. Advantages compared to conventional periodic internal quality control (IQC) include absence of commutability problems and continuous monitoring of performance. We implemented MA QC for multiple routine hematology and chemistry parameters.

Thyroid antibodies and levothyroxine effects in subclinical hypothyroidism: A pooled analysis of two randomized controlled trials.

Background: Antithyroid antibodies increase the likelihood of developing overt hypothyroidism, but their clinical utility remains unclear. No large randomized controlled trial (RCT) has assessed whether older adults with subclinical hypothyroidism (SHypo) caused by autoimmune thyroid disease derive more benefits from levothyroxine treatment (LT4).

Objective: To determine whether older adults with SHypo and positive antibodies derive more clinical benefits from LT4 than those with negative antibodies.

Indirect determination of biochemistry reference intervals using outpatient data.

The aim of this study was to determine reference intervals in an outpatient population from Vall d'Hebron laboratory using an indirect approach previously described in a Dutch population (NUMBER project). We used anonymized test results from individuals visiting general practitioners and analysed during 2018. Analytical quality was assured by EQA performance, daily average monitoring and by assessing longitudinal accuracy between 2018 and 2020 (using trueness verifiers from Dutch EQA).

Incorporating Baseline Outcome Data in Individual Participant Data Meta-Analysis of Non-randomized Studies.

Background: In non-randomized studies (NRSs) where a continuous outcome variable (e.g., depressive symptoms) is assessed at baseline and follow-up, it is common to observe imbalance of the baseline values between the treatment/exposure group and control group.

No Effect of Levothyroxine on Hemoglobin in Older Adults With Subclinical Hypothyroidism: Pooled Results From 2 Randomized Controlled Trials.

Context: Subclinical thyroid dysfunction and anemia are common disorders, and both have increasing prevalence with advancing age.

Objective: The aim of this study was to assess whether levothyroxine treatment leads to a rise in hemoglobin levels in older persons with subclinical hypothyroidism.

Methods: This preplanned combined analysis of 2 randomized controlled trials included community-dwelling persons aged 65 years and older with subclinical hypothyroidism who were randomly assigned to levothyroxine or placebo treatment.

Thyroid Function and Risk of Anemia: A Multivariable-Adjusted and Mendelian Randomization Analysis in the UK Biobank.

Context: Thyroid dysfunction is associated with higher anemia prevalence, although causality remains unclear.

Objective: This study aimed to investigate the association between thyroid function and anemia.

Methods: This cross-sectional and Mendelian randomization study included 445 482 European participants from the UK Biobank (mean age 56.

Association of Thyroid Dysfunction With Cognitive Function: An Individual Participant Data Analysis.

Importance: In clinical guidelines, overt and subclinical thyroid dysfunction are mentioned as causal and treatable factors for cognitive decline. However, the scientific literature on these associations shows inconsistent findings.

Objective: To assess cross-sectional and longitudinal associations of baseline thyroid dysfunction with cognitive function and dementia.

The effects of single and a combination of determinants of anaemia in the very old: results from the TULIPS consortium.

Background And Objectives: Nutritional deficiencies, renal impairment and chronic inflammation are commonly mentioned determinants of anaemia. The aim of this study was to investigate the effects of these determinants, singly and in combination, on anaemia in the very old.

Method: The TULIPS Consortium consists of four population-based studies in oldest-old individuals: Leiden 85-plus Study, LiLACS NZ, Newcastle 85+ study, and TOOTH.

Levothyroxine Treatment and Cardiovascular Outcomes in Older People With Subclinical Hypothyroidism: Pooled Individual Results of Two Randomised Controlled Trials.

Background: The cardiovascular effects of treating older adults with subclinical hypothyroidism (SCH) are uncertain. Although concerns have been raised regarding a potential increase in cardiovascular side effects from thyroid hormone replacement, undertreatment may also increase the risk of cardiovascular events, especially for patients with cardiovascular disease (CVD).

Objective: To determine the effects of levothyroxine treatment on cardiovascular outcomes in older adults with SCH.

Correction: Statin Use and Self-Reported Hindering Muscle Complaints in Older Persons: A Population Based Study.

[This corrects the article DOI: 10.1371/journal.pone.

Older individuals' views on their personal screening results for complex health problems: a qualitative study.

Background: Providing older persons with information about their health status may increase their involvement in their own health and enhance self-management. However, we need a better understanding of how older persons view their personal results after completing a screening questionnaire on complex health, of their (lack of) motivation and their subsequent action.

Methods: In this qualitative study community-dwelling older persons (≥80 years, n = 13) who completed a screening questionnaire on complex health problems were interviewed regarding their perception of the results, the actions they considered taking and their personal motivations.

Outcomes of Thyroid Dysfunction in People Aged Eighty Years and Older: An Individual Patient Data Meta-Analysis of Four Prospective Studies (Towards Understanding Longitudinal International Older People Studies Consortium).

Subclinical and overt thyroid dysfunction is easily detectable, often modifiable, and, in younger age groups, has been associated with clinically relevant outcomes. Robust associations in very old persons, however, are currently lacking. This study aimed to investigate the associations between (sub-)clinical thyroid dysfunction and disability in daily living, cognitive function, depressive symptoms, physical function, and mortality in people aged 80 years and older.