Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “instrumental variable”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 109 records · Page 6Linked to original sources
PubMed1977

Socio-psychological factors and metabolic control in juvenile diabetes.

The influence of exogenous and environmental factors on metabolic control was studied in 58 insulin treated juvenile diabetics, 6-17 years of age. Duration of diabetes varied between 3-14 years and age at onset of diabetes between 1-13 years. The social situation as well as knowledge about and attitudes towards diabetes among the patients and their parents were estimated by interviews, questionnaires and special tests. The quality of the diet, exercise and insulin treatment was assessed. An index of diabetic control was calculated on the basis of the patients daily urinalysis made at home. Multiple regression analysis and a special statistical "instrumental" variable technique were used in an effort to analyse the correlations between all variables. The social situation of the diabetic children was comparable with that of other Swedish children, but many parents felt the economic burden of the diabetic treatment as a problem. Knowledge tests showed that 25% of the parents and 62% of the patients above 12 years had unsatisfactory knowledge about diabetes. However, 93% of the patients seemed to have predominantly positive attitudes towards the treatment. Severe psychological problems had occurred in 7 cases. Food habits were appropriate among 21% of the patients and 26% had very regular exercise customs. Physical exercise seemed to be the most important of the exogenous factors for the diabetic control (p less than 0.001). Among teenagers knowledge was positively correlated to positive attitudes which in turn were positively correlated to physical exercise. Instrumental variable technique gave further indications of a positive influence of knowledge on control, and the correlation between diabetic control on one hand and knowledge combined with positive attitudes on the other was significantly positive. The results emphasize the importance of assisting young diabetic patients and their families in their socio-psychological adaptation to the strains of diabetic therapy.

Adolescent↗
PubMed2005

Are primary care services a substitute or complement for specialty and inpatient services?

OBJECTIVE: To determine whether strategies designed to increase members' use of primary care services result in decreases (substitution) or increases (complementation) in the use and cost of other types of health services. STUDY SETTING: Encounter and cost data were extracted from the Department of Veterans Affairs (VA) administrative data sources for the period 1995-1999. This timeframe captures the VA's natural experiment of increasing geographic access to primary care by establishing new satellite primary care clinics, known as Community-Based Outpatient Clinics (CBOCs). STUDY DESIGN: We exploited this natural experiment to estimate the substitutability of primary care for other health services and its impact on cost. Hypotheses were tested using ordinary least squares (OLS) regression, which was potentially subject to endogeneity bias. Endogeneity bias was assessed using a Hausman test. Endogeneity bias was accounted for by using instrumental variables analysis, which capitalized on the establishment of CBOCs to provide an exogenous identifier (change in travel distance to primary care). DATA COLLECTION: Demographic, encounter, and cost data were collected for all veterans using VA health services who resided in the catchment areas of new CBOCs and for a matched group of veterans residing outside CBOC catchment areas. PRINCIPAL FINDINGS: Change in distance to primary care was a significant and substantial predictor of change in primary care visits. OLS analyses indicated that an increase in primary care service use was associated with increases in the use of all specialty outpatient services and inpatient services, as well as increases in inpatient and outpatient costs. Hausman tests confirmed that OLS results for specialty mental health encounters and mental health admissions were unbiased, but that results for specialty medical encounters, physical health admissions, and outpatient costs were biased. Instrumental variables analyses indicated that an increase in primary care encounters was associated with a decrease in specialty medical encounters and was not associated with an increase in physical health admissions, or outpatient costs. CONCLUSIONS: Results provide evidence that health systems can implement strategies to encourage their members to use more primary care services without driving up physical health costs.

Adult↗
PubMed2004

Impact of early newborn discharge legislation and early follow-up visits on infant outcomes in a state Medicaid population.

OBJECTIVE: Scant information exists on the effects of legislation mandating coverage of minimum postnatal hospital stays on infant health outcomes. There are also gaps in knowledge regarding the effectiveness of early follow-up visits for newborns. The objective of this study was to determine the impact of 1) legislation mandating coverage of minimum postnatal hospital stays and 2) early follow-up visits by the age of 4 days on infant outcomes during the first month of life. METHODS: A retrospective analysis was conducted of Ohio Medicaid claims data linked with birth certificate data for the period 1991-1998. The impact of the legislation was evaluated using interrupted time-series analysis of health-related utilization. The effects of early follow-up visits for vaginally delivered newborns with short stays were analyzed using the day of the week on which the birth occurred (eg, Monday, Tuesday) as an instrumental variable to account for potential confounding. A total of 155,352 full-term newborns who were born to mothers who receive Medicaid were studied. The main outcomes measured were rehospitalizations, emergency department (ED) visits, and diagnoses of dehydration and infection within 10 and 21 days of birth. RESULTS: Few outcomes exhibited significant changes after legislation mandating coverage of minimum postnatal hospital stays. Rates of rehospitalization for jaundice within 10 days of birth fell from 0.78% to 0.47% in the year after legislation was introduced but leveled off after the legislation took effect. Rates of ED visits within 21 days increased from 6.0% to 10.4% during periods of increasing short stay but fell to 8.0% during the year after introduction of the legislation and leveled off when the legislation took effect. Rates of all-cause rehospitalization, dehydration, and infection diagnoses showed no consistent relationship to Ohio's legislation. Using instrumental variable analysis, newborns who received early follow-up visits were significantly less likely to have rehospitalizations within the first 10 days of life than those who did not. CONCLUSIONS: In this state Medicaid population, legislation mandating coverage of minimum postnatal hospital stays was associated with reductions in the rates of rehospitalization for jaundice and ED visits. For newborns with short stays, early follow-up visits may reduce rehospitalizations in the early postpartum period.

Dehydration↗
PubMed2025

Exploring the causal association between television viewing and meniscal injuries: A two-sample Mendelian randomization analysis.

The aim of this study was to assess whether there is a potential causal relationship between sedentary behavior and meniscal injuries based on the Mendelian randomization (MR) method. This study used a two-sample MR design to integrate pooled data from a large-scale genome-wide association studies (GWAS). Single nucleotide polymorphisms (SNPs) that were significantly associated with sedentary behavior (represented by daily TV-viewing time) and independent of each other were selected as instrumental variables, while focusing on data from populations of European ancestry. To ensure the robustness and reliability of the analyses, 3 mainstream MR analysis methods were combined in this study: inverse variance weighted (IVW), weighted median estimation (WME) and MR-Egger regression. Heterogeneity test, horizontal multivariate analysis, and leave-one-out sensitivity test were also conducted to further validate the stability of causal estimation. The results of the IVW method showed that sedentary behavior was significantly associated with the risk of meniscus injury, with an OR (95% CI) of 2.93 (1.89-4.52), and a P-value of&#x2005;<&#x2005;.001, suggesting that sedentary behavior may be an important risk factor for meniscus injury. No significant bias was found in the heterogeneity test and the assessment of multiple validity, and the sensitivity analysis showed that the effect of individual SNPs on the overall estimation was small, and the results had good robustness. This study provides genetic epidemiological evidence of a positive causal effect of sedentary behavior on meniscal injuries based on a causal inference approach with genetic instrumental variables. The results suggest that reducing sedentary time, especially prolonged TV watching behavior, may reduce the risk of meniscus injury to some extent.

Humans↗
PubMed2000

The standardized-taper root canal preparation--Part 1. Concepts for variably tapered shaping instruments.

AIM: To introduce the concept of variable taper instruments for predictable and ergonomic root canal preparation, and demonstrate the design features of Greater Taper files. SUMMARY: Optimal root canal shaping is difficult to practice and teach with traditional instruments. Instrument sequences are complex, with up to 18 instruments and 63 procedural stages, providing almost limitless scope for poor results and iatrogenic error. In the first of six articles, Dr Buchanan describes the Variable Taper concept, which grew from such frustrations, and represents a new concept in file design. Milled from NiTi alloys in tapers of 0.06, 0.08, 0.10 and 0.12 mm mm-1, with accessory files for wide canals, their design embodies the key shaping features of adequate coronal enlargement, full deep shape, and predictable apical resistance form case after case. The ease and simplicity of their use is described, and enhanced cleaning and obturation outcomes discussed in relation to their unique design features. KEY LEARNING POINTS: Canal preparation is difficult to practice and teach with traditional K-files and Gates Glidden drills. Variable Taper files are designed to offer the optimal preparation features of adequate (not excessive) coronal enlargement, full deep shape, and apical resistance form in a simple instrument sequence. Variable Taper technique is simple to master, and offers predictable cleaning and obturation outcomes, even in inexperienced hands.

Dental Alloys↗
PubMed2006

Quality improvement implementation and hospital performance on quality indicators.

OBJECTIVE: To examine the association between the scope of quality improvement (QI) implementation in hospitals and hospital performance on selected indicators of clinical quality. DATA SOURCES: Secondary data from 1997 mailed survey of hospital QI practices, Medicare Inpatient Database, American Hospital Association's Annual Survey of Hospitals, the Bureau of Health Professions' Area Resource File, and two proprietary data sets compiled by Solucient Inc. containing data on managed care penetration and hospital financial performance. STUDY DESIGN: Cross-sectional study of 1,784 community hospitals to assess relationship between QI implementation approach and six hospital-level quality indicators. DATA COLLECTION/ABSTRACTION METHODS: Two-stage instrumental variables estimation in which predicted values (instruments) of four QI scope variables and control (exogenous) variables used to estimate hospital-level quality indicators. PRINCIPAL FINDINGS: Involvement by multiple hospital units in QI effort is associated with worse values on hospital-level quality indicators. Percentage of hospital staff and percentage of senior managers participating in formally organized QI teams are associated with better values on quality indicators. Percentage of physicians participating in QI teams is not associated with better values on the hospital-level quality indicators studied. CONCLUSIONS: Results supported the proposition that the scope of QI implementation in hospitals is significantly associated with hospital-level quality indicators. However, the direction of the association varied across different measures of QI implementation scope.

Cross-Sectional Studies↗
PubMed1989

Transcutaneous bilirubinometry. Interinstrumental variability of TcB instruments.

We studied the interinstrumental variability of the transcutaneous bilirubin meter (TcB) in 35 high risk neonates, using eight commercially available TcB instruments. Our study showed that commercially available TcB instruments were stable and had little interinstrumental variability for repeated TcB measurements at the forehead, chest, and sternum.

Bilirubin↗
PubMed2006

Variability of spinal instrumentation configurations in adolescent idiopathic scoliosis.

Surgical instrumentation for the correction of adolescent idiopathic scoliosis (AIS) is a complex procedure involving many difficult decisions (i.e. spinal segment to instrument, type/location/number of hooks or screws, rod diameter/length/shape, implant attachment order, amount of rod rotation, etc.). Recent advances in instrumentation technology have brought a large increase in the number of options. Despite numerous clinical publications, there is still no consensus on the optimal surgical plan for each curve type. The objective of this study was to document and analyse instrumentation configuration and strategy variability. Five females (12-19 years) with AIS and an indication for posterior surgical instrumentation and fusion were selected. Curve patterns were as follows: two right thoracic (Cobb: 34 degrees, 52 degrees), two right thoracic and left lumbar (Cobb T/L: 57 degrees/45 degrees, 72 degrees/70 degrees) and 1 left thoraco-lumbar (Cobb: 64 degrees). The pre-operative standing postero-anterior and lateral radiographs, supine side bending radiographs, a three-dimensional (3D) reconstruction of the spine, pertinent 3D measurements as well as clinical information such as age and gender of each patient were submitted to six experienced independent spinal deformity surgeons, who were asked to provide their preferred surgical planning using a posterior spinal approach. The following data were recorded using the graphical user interface of a spine surgery simulator (6x5 cases): implant types, vertebral level, position and 3D orientation of implants, anterior release levels, rod diameter and shape, attachment sequence, rod rotation (angle, direction), adjustments (screw rotation, contraction/distraction), etc. Overall, the number of implants used ranged from 11 to 26 per patient (average 16; SD +/-4). Of these, 45% were mono-axial screws, 31% multi-axial screws and 24% hooks. At one extremity of the spectrum, one surgeon used only mono-axial screws, while at the other, another surgeon used 81% hooks. The selected superior- and inferior-instrumented vertebrae varied up to six and five levels, respectively (STD 1.2 and 1.5). A top-to-bottom attachment sequence was selected in 61% of the cases, a bottom-up in 29% and an alternate order in 11%. The rod rotation maneuver of the first rod varied from 0 degrees (no rotation) to 140 degrees, with a median at 90 degrees. In conclusion, a large variability of instrumentation strategy in AIS was documented within a small experienced group of spinal deformity surgeons. The exact cause of this large variability is unclear but warrants further investigation with multicenter outcome studies as well as experimental and computer simulation studies. We hypothesize that this variability may be attributed to different objectives for correction, to surgeon's personal preferences based on their previous experience, to the known inter-observer variability of current classification systems and to the current lack of clearly defined strategies or rational rules based on the validated biomechanical studies with modern multi-segmental instrumentation systems.

Adolescent↗
PubMed1978

A variable focus telescopic instrument for indirect ophthalmoscopy with increased magnification and stereopsis.

We devised a new binocular indirect ophthalmoscope and a complimentary examination technique that provide enhanced fundus magnification and optimum stereopsis through a wide range of patient pupillary apertures. The lightweight, mechanically simple instrument uses a variable focus Galilean telescopic observation system to enlarge the condensing lens image of the fundus seen by the examiner. The present device is capable of about X 1.5 fundus magnification with negligible stereopsis through a 20-mm patient pupil, continuously increasing to X 8.5 with greatly enhanced stereopsis through an 8-mm pupil. A zoom focusing capability considerably extends the magnification, stereopsis, and small pupip penetrating characteristics of a given condensing lens by allowing the examiner to binocularly observe the telescopically magnified fundus image throughout the 30-cm to 60-cm focusing range of the ophthalmoscope.

Fundus Oculi↗
PubMed2006

The impact of cost sharing of prescription drug expenditures on health care utilization by the elderly: own- and cross-price elasticities.

PURPOSE: To estimate healthcare demand elasticity and evaluate the impact of deductible/co-payment policy changes for prescription drugs on the use of drugs and physician visits among seniors with rheumatoid arthritis (RA) in British Columbia (BC), Canada. METHODS: According to the BC drug insurance program, prior to 2002, seniors co-paid the dispensing fee of each prescription to an annual maximum of CAN$ 200 (plan A). Starting in 2002, this plan was split into plan A and plan A1 (Premium Assistance) such that the co-payment amount equaled a maximum of CAN$ 25 and CAN$ 10 per prescription to an annual maximum of CAN$ 275 and CAN$ 200, respectively. Because of the endogeneity of the beneficiary price in the presence of a non-linear price schedule resulting from the cost-sharing policy, we implemented the method of instrumental variables to estimate price elasticities. The instrument was based on the price an individual would face under the new cost-sharing policy if their consumption remained at the pre-policy level. RESULTS: A total of 8017 patients were included. The estimated own-price elasticity of demand for prescription drugs and the cross-price elasticity of demand for physician visits were found to be negative and positive, respectively. The implications of our findings were that when cost sharing for prescription drugs increased, the demand for prescription drugs decreased and the demand for physician visits increased. CONCLUSIONS: In a predominantly publicly funded health care system, the selective introduction of market driven cost containment concepts such as patient cost-sharing might have the unintended impact of increasing overall health utilization for seniors with RA.

Aged↗
PubMed2002

European Concerted Action on Anticoagulation (ECAA): International Normalized Ratio variability of CoaguChek and TAS point-of-care testing whole blood prothrombin time monitors.

The object was to assess the variability in displayed International Normalised Ratio (INR) between monitors of the same manufacture using whole blood samples from the same subjects. Two brands of monitor, CoaguChek Mini and the TAS PT-NC were tested. 14 instruments of each brand were tested on the same day at the same laboratory by the same operator using identical blood samples to avoid between-centre differences in samples and operator technique. Whole blood samples from two normal donors and four coumarin-treated patients were tested to assess between-instrument variability of INR. Results have been coded. There was a much wider dispersion of INR on Brand B than on Brand A. One Brand A instrument failed to give a result with one of the two whole blood samples from one patient. One Brand B monitor gave an aberrant result with one of the samples from a normal subject. On both brands of monitor, INR variability appeared to be due mainly to duplication differences rather than between-instrument variability on both normal and coumarin whole blood samples.

Analysis of Variance↗
PubMed1999

Duplicate coverage and demand for health care. The case of Catalonia.

An individual has duplicate coverage when he enjoys a compulsory medical public insurance, and in addition he has purchased a private one. This paper studies the implications of duplicate coverage on both demand for visits to specialists and on the selection process of the private insurance market. Econometric models, estimated by the generalized method of moments, accommodate both the endogeneity of insurance choice decision and the non-negativity of the variable number of visits. The choice of instrumental variables is motivated within a theoretical model of demand for health care. The results shows that endogeneity is important for the subsample of heads of household, but not for the subsample of non-heads of household. For the subsample of non-heads of household, a positive effect of duplicate coverage on the number of visits to specialists is found. Health related variables, education and income are also important. Results are consistent with the idea that heads of household that buy private insurance are the ones with poor unobservable health conditions. It is argued that this last result is related to the existence of a compulsory public insurance.

Health Services Needs and Demand↗
PubMed2026

Assessing the Association Between Age at First Sexual Intercourse and HIV Infection Risk Using A Two-sample Mendelian Randomization Framework.

This study applied a two-sample Mendelian randomization framework to investigate the potential association between age at first sexual intercourse (AFS) and the risk of Human Immunodeficiency Virus (HIV) infection. Summary-level Genome-Wide Association Study (GWAS) data from European populations were analyzed, including 214,547 individuals for AFS and 357 HIV cases with 218,435 controls from the FinnGen R5 dataset. Independent single-nucleotide polymorphisms significantly associated with AFS were selected as instrumental variables following linkage disequilibrium clumping and instrument-strength assessment. Causal estimates were evaluated using inverse-variance weighting (IVW), MR-Egger regression, weighted median, weighted mode, and simple mode. Cochran's Q test, MR-Egger intercept analysis, MR-PRESSO assessment, and leave-one-out sensitivity analyses were performed to evaluate heterogeneity, pleiotropy, and robustness. The IVW analysis suggested that genetically predicted later AFS was associated with reduced HIV infection risk (OR = 0.192, 95% CI = 0.062-0.592, P = 0.004), whereas earlier sexual debut corresponded to increased HIV susceptibility. Directionally consistent findings across multiple Mendelian randomization methods supported the stability of the observed association. However, the findings should be interpreted cautiously because the HIV outcome analysis relied on a single dataset with a limited number of HIV cases. These results support a potential association between earlier sexual debut and HIV susceptibility and demonstrate the utility of Mendelian randomization for investigating behavioral risk factors associated with infectious disease outcomes.

Humans↗
PubMed2026

Causal Relationship Between Ischemic Stroke and Vascular Dementia: A Mendelian Randomization Study.

Ischemic stroke (IS) is a major cause of disability and mortality worldwide, and vascular dementia (VaD) is a common dementia subtype associated with cerebrovascular injury. Observational studies have suggested a relationship between IS and VaD, but these studies are vulnerable to confounding and reverse causality. This protocol describes a reproducible two-sample Mendelian randomization (MR) workflow for evaluating the potential causal association between IS and VaD using publicly available genome-wide association study (GWAS) summary statistics. Genetic instruments associated with IS were extracted from a public GWAS dataset, and outcome associations for VaD were obtained from a public VaD GWAS dataset. The corresponding dataset IDs are provided in the Protocol section. After outcome matching and allele harmonization, 51 single-nucleotide polymorphisms (SNPs) were retained for the final MR analysis. The workflow includes instrumental variable selection, linkage disequilibrium clumping, allele harmonization, instrument strength assessment, inverse variance weighted (IVW) analysis, weighted median analysis, MR-Egger analysis, heterogeneity testing, horizontal pleiotropy assessment, and leave-one-out sensitivity analysis. In the representative analysis, the IVW method showed a positive association between genetically predicted IS and VaD risk, and the weighted median method yielded a directionally concordant result. The MR-Egger estimate was directionally consistent but did not reach statistical significance. Therefore, these findings should be interpreted as suggestive evidence of a possible causal effect, rather than definitive proof of causality. This protocol may help researchers apply a transparent and reproducible MR workflow to investigate cerebrovascular disease-related outcomes using public GWAS data.

Humans↗
PubMed2025

No More Free Lunch: Challenges to Mendelian Randomization Due to Sample Selection and Complex Methods.

Mendelian randomization (MR) is increasingly used in epidemiological studies to investigate causal relationships. MR depends on 3 fundamental instrumental variable assumptions: relevance, independence, and exclusion restriction. Studies often assume that MR mitigates bias from confounding due to the random allocation of genetic variants at conception. In this perspective, using causal directed acyclic graphs, we discuss several scenarios where biases in MR analyses may arise due to the nature of the data or methods being used. These include (1) collider bias due to the nonrandom selection of participants into study populations used for conducting genome-wide association studies (GWAS), (2) indirect genetic effects arising from population-based GWAS rather than within-family studies, and (3) collider bias due to gene-environment interaction effects on the exposure in nonlinear MR analyses. We provide practical considerations for examining and reducing these biases in MR analyses.

Humans↗
PubMed2026

The Association of Allergic Rhinitis with Chronic Adenotonsillar Diseases and Chronic Rhinosinusitis: A Mendelian Randomization Study.

INTRODUCTION: Allergic rhinitis (AR) has long been considered to be associated with chronic adenotonsillar disease (CATD). However, their causal relationship remains unclear. This study aims to investigate the causal relationship between AR and CATD and to examine the mediating role of chronic rhinosinusitis (CRS) in this association. METHODS: This study employed a two-sample Mendelian randomization (MR) design using genetic instrumental variable analysis. Data for allergic rhinitis (AR) were obtained from the MRC IEU OpenGWAS data infrastructure, data for chronic adenotonsillar disease (CATD) from the FinnGen biobank, and data for chronic rhinosinusitis (CRS) from the GWAS Catalog. Several MR methods were applied. In addition, a two-step MR approach was used to investigate the mediating role of CRS in the relationship between AR and CATD. RESULTS: MR analysis identified a positive correlation between AR and CATD. IVW and weighted median analyses showed significant causal effects (beta = 0.55, 95% CI: 0.26 to 0.84); p <0.001). No causal association was found between CATD and AR. AR and CRS showed a positive correlation (beta = 1.38, 95% CI: 0.78 to 1.98; p = 6.5 &#xd7; 10-6). CRS had a beta value of 0.15 (95% CI: 0.06 to 0.24; p = 0.001) for CATD. CRS mediates 37.6% of the AR to CATD pathway (mediation effect = 0.20, 95% CI: 0.04 to 0.37; p = 0.013). DISCUSSION: These findings indicate that AR may contribute to CATD risk through CRS, highlighting the need for further research to explore underlying biological mechanisms and validate these findings. CONCLUSIONS: This study suggests a positive causal relationship between AR and CATD, with CRS acting as a mediator.

Mendelian Randomization Analysis↗
PubMed2026

Causal relationship between asthma and hernia risk: A Mendelian randomization study.

Epidemiological associations between asthma and various hernia subtypes have been reported, but the causality and direction remain unclear. This study employs a two&#x2011;sample Mendelian randomization (MR) approach to systematically assess the causal associations between asthma and 6 hernia subtypes. Using publicly available summary data of genome-wide association studies, asthma was selected as the exposure, and diaphragmatic hernia, umbilical hernia, femoral hernia, hiatus hernia, inguinal hernia, and ventral hernia were selected as outcomes. Instrumental variables were strictly screened (F-statistic&#x2005;>&#x2005;10). The inverse&#x2011;variance weighted method was used as the primary analytical approach, supplemented with MR Egger and weighted median methods. Sensitivity analyses included heterogeneity tests, horizontal pleiotropy tests, Steiger directionality tests, leave&#x2011;one&#x2011;out analyses, and Radial MR. Reverse MR was performed for validation. Forward MR analyses revealed a significant positive causal effect of asthma on diaphragmatic hernia (odds ratio [OR]&#x2005;=&#x2005;1.19, 95% confidence interval [CI]: 1.08-1.31, P&#x2005;<&#x2005;.001) and a suggestive association with umbilical hernia (OR&#x2005;=&#x2005;1.19, 95% CI: 1.05-1.34, P&#x2005;=&#x2005;.007). The umbilical hernia association was significant only by the inverse&#x2011;variance weighted method; weighted median (P&#x2005;=&#x2005;.102) and MR-Egger (P&#x2005;=&#x2005;.210) estimates were not statistically significant, and the estimate attenuated after outlier removal (confirmatory OR&#x2005;=&#x2005;1.13, 95% CI: 1.01-1.26, P&#x2005;=&#x2005;.028). Sensitivity analyses showed no significant heterogeneity or pleiotropy. Reverse MR did not identify significant causal effects of hernias on asthma, although power limitations for certain hernia subtypes should be considered. No significant associations were observed between asthma and the other hernia subtypes, although the null findings for femoral and ventral hernias should be interpreted with caution due to limited statistical power. This study provides genetic evidence supporting asthma as a causal risk factor for diaphragmatic hernia, with a suggestive association for umbilical hernia. The diaphragmatic hernia finding was robust across multiple sensitivity analyses, whereas the umbilical hernia association was less consistent and requires further confirmation. These findings contribute to a deeper understanding of the mechanistic links between asthma and specific hernia subtypes.

Mendelian Randomization Analysis↗