PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “causality”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

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

At least 1,621 records · Page 90Linked to original sources
PubMed2026

Association of gestational diabetes with other lactation-related disorders: A 2-sample Mendelian randomization analysis of causal effects.

Gestational diabetes mellitus (GDM) is associated with adverse metabolic outcomes and may also be related to postpartum breast and lactation disorders. Observational studies are susceptible to confounding and reverse causation. We used a 2-sample Mendelian randomization design to examine the association between genetic liability to GDM and other disorders of the breast and lactation associated with childbirth. Genetic liability to GDM was associated with higher odds of a composite phenotype of breast and lactation disorders associated with childbirth. Replication using independent samples and more specific clinical outcomes is required. Summary statistics for GDM and the FinnGen outcome "other disorders of breast and lactation associated with childbirth" were obtained from the Integrative Epidemiology Unit open genome-wide association study resource. single nucleotide polymorphisms associated with GDM (P&#x2005;<&#x2005;5&#x2009;&#xd7;&#x2009;10-6) were clumped (R2&#x2005;<&#x2005;0.001) within 10,000&#x2009;kb. The inverse-variance weighted method was the primary analysis; Mendelian randomization-Egger, weighted median, simple mode, and weighted mode analyses were complementary methods. Heterogeneity, directional horizontal pleiotropy, leave-one-out, and Steiger directionality analyses were performed. Nineteen single nucleotide polymorphisms were retained; F statistics ranged from 21.08 to 288.04. Genetic liability to GDM was associated with higher odds of the outcome in the inverse-variance weighted analysis (odds ratio [OR], 1.50; 95% confidence interval [CI], 1.08-2.09; P&#x2005;=&#x2005;.0165). The weighted median (OR, 1.76; 95% CI, 1.09-2.84; P&#x2005;=&#x2005;.0216) and weighted mode estimates (OR, 1.98; 95% CI, 1.21-3.26; P&#x2005;=&#x2005;.0148) were directionally consistent. There was no statistical evidence of heterogeneity or directional horizontal pleiotropy. The Steiger test supported the direction from GDM to the outcome (P&#x2005;=&#x2005;1.30&#x2005;&#xd7;&#x2005;10-11).

Diabetes, Gestational↗
PubMed2003

Estimating causal treatment effects from longitudinal HIV natural history studies using marginal structural models.

Several recently completed and ongoing studies of the natural history of HIV infection have generated a wealth of information about its clinical progression and how this progression is altered by therepeutic interventions and environmental factors. Natural history studies typically follow prospective cohort designs, and enroll large numbers of participants for long-term prospective follow-up (up to several years). Using data from the HIV Epidemiology Research Study (HERS), a six-year natural history study that enrolled 871 HIV-infected women starting in 1993, we investigate the therapeutic effect of highly active antiretroviral therapy regimens (HAART) on CD4 cell count using the marginal structural modeling framework and associated estimation procedures based on inverse-probability weighting (developed by Robins and colleagues). To evaluate treatment effects from a natural history study, specialized methods are needed because treatments are not randomly prescribed and, in particular, the treatment-response relationship can be confounded by variables that are time-varying. Our analysis uses CD4 data on all follow-up visits over a two-year period, and includes sensitivity analyses to investigate potential biases attributable to unmeasured confounding. Strategies for selecting ranges of a sensitivity parameter are given, as are intervals for treatment effect that reflect uncertainty attributable both to sampling and to lack of knowledge about the nature and existence of unmeasured confounding. To our knowledge, this is the first use in "real data" of Robins's sensitivity analysis for unmeasured confounding (Robins, 1999a, Synthese 121, 151-179). The findings from our analysis are consistent with recent treatment guidelines set by the U.S. Panel of the International AIDS Society (Carpenter et al., 2000, Journal of the American Medical Association 280, 381-391).

Antiretroviral Therapy, Highly Active↗
PubMed2003

DNA variation in a 13-Mb region including the F9 gene: inferring the genealogical history and causal role of a hemophilia B mutation (IVS 5+13 A-->G).

About 5.5% of all UK hemophilia B patients have the base substitution IVS 5+13 A-->G as the only change in their factor (F)IX gene (F9). This generates a novel donor splice site which fits the consensus better than the normal intron 5 donor splice. Use of the novel splice site should result in a missense mutation followed by the abnormal addition of four amino acids to the patients' FIX. In order to explain the prevalence of this mutation, its genealogical history is examined. Analysis of restriction fragment length polymorphism in the 21 reference UK individuals (from different families) with the above mutation showed identical haplotypes in 19 while two differed from the rest and from each other. In order to investigate the history of the mutation and to verify that it had occurred independently more than once, the sequence variation in 1.5-kb segments scattered over a 13-Mb region including F9 was examined in 18 patients and 15 controls. This variation was then analyzed with a recently developed Bayesian approach that reconstructs the genealogy of the gene investigated while providing evidence of independent mutations that contribute disconnected branches to the genealogical tree. The method also provides minimum estimates of the age of the mutation inherited by the members of coherent trees. This revealed that 17 or 18 mutant genes descend from a founder who probably lived 450 years ago, while one patient carries an independent mutation. The independent recurrence of the IVS5+13 A-->G mutation strongly supports the conclusion that it is the cause of these patients' mild hemophilia.

Base Sequence↗
PubMed1996

The causality field (extrinsic and intrinsic factors) in industrial subacute low back pain patients.

In a prospective, randomized study, primarily designed to test the efficacy of activation on consecutive blue-collar workers sick-listed for 6 weeks due to subacute low back pain, 25% of the workers were excluded for medical reasons. In the intervention study (n = 103), only a minority of cases (6%) had 'true' subacute complaints, i.e. no prior history of low back pain. Subjective reports on general well-being, health status and work-related ergonomic factors were significantly lower or worse in patients than in reference samples. The randomized intervention study could establish a significant effect of graded activation on work return, but the effect seemed to be restricted to patients moderately disabled, i.e. one-third of the subacute low back pain patients included. A predictive four-factor model on work return increased the possibility of identifing nonresponders (chronic low back pain) more than threefold with a specificity (91%) and sensitivity (74%) comparable to that of clinical disc herniation. The history of a prolonged disablement process, cognitive factors, pain behavior and mentally straining ergonomic factors seemed to be of importance. Psychological reactions, or 'barriers to recovery', were slightly different in treatment and control groups but the type of intervention did not significantly alter the predictive model, suggesting that subsets of the study sample may benefit from other optional functional approaches. Descriptive characteristics of the study sample emphasized that subacute low back pain patients cannot be conceptualized as a homogeneous group. Four sub-groups could be identified: (a) specific medical disorders; (b) spontaneous recovery group; (c) moderately disabled back pain patients; and (d) nonresponders. The results support proposals that treatment should be tailored according to individual needs and that better case management should have priority for those belonging to the nonresponder group.

Adult↗