ArticleBMJ open respiratory research2026
Relationship between serum cystatin C and long-term mortality in patients with self-reported COPD: evidence from two large population-based surveys.
Article in BMJ open respiratory research, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.
What it found
Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.
The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.
Who cites it
0 citing papers in PubMed.
No citing paper in PubMed yet.
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
9 authors.
Funding
No grant is acknowledged in the PubMed record.
Abstract
introductionSerum cystatin C (Cys-C) is an indicator of ageing, and its connection with the long-term prognosis in patients with chronic obstructive pulmonary disease (COPD) is poorly understood. We aimed to examine the association between Cys-C levels and long-term mortality in patients with COPD.
methodsThis cohort study used data from the China Health and Retirement Longitudinal Study (CHARLS) and the National Health and Nutrition Examination Survey (NHANES). We included patients with COPD with Cys-C data from 2011 in CHARLS and 1999-2004 in NHANES. We analysed the association between Cys-C and long-term mortality in COPD using multivariate logistic regression and Cox regression. Multiple models were adjusted to reduce potential bias. Fitted curves were used to analyse the dose-response relationship between Cys-C and long-term mortality. Receiver operating characteristic (ROC) curve and subgroup analyses were also performed.
results1030 patients with COPD from two cohorts were included in our study. When grouped by Cys-C quartiles, the high Cys-C Q4 group was older and had higher proportions of males and a higher mortality rate. Regression analysis showed a positive association between Cys-C and long-term mortality in COPD after adjusting for covariates (CHARLS: OR=3.34, 95% CI 1.51 to 7.38, p=0.003; NHANES: HR=1.35, 95% CI 1.02 to 1.75, p=0.033). Analysing the data in a categorical fashion using quartiles, the Q4 group (CHARLS: OR=2.80, 95% CI 1.07 to 7.33, p=0.036; NHANES: HR=2.12, 95% CI 1.08 to 4.19, p=0.030) had a higher mortality rate compared with the Q1 group. The area under the curve for ROC was 73.7% (CHARLS) and 73.3% (NHANES). The results of subgroup analyses showed an interaction of sex in Cys-C and COPD mortality (p for interaction=0.035 in CHARLS and 0.042 in NHANES), with a more pronounced effect on females.
conclusionsOur study found that high Cys-C was related to increased long-term mortality in patients with COPD. This association appears more pronounced in females.
Indexed as
Identifiers
What OpenQuestion holds
Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.