Predicting COPD 1-year mortality using prognostic predictors routinely measured in primary care.

Area of Science:

• Pulmonary Medicine
• Health Services Research
• Biostatistics

Background:

• Chronic obstructive pulmonary disease (COPD) significantly contributes to mortality and reduces patient quality of life.
• Palliative care is recommended for advanced COPD patients in their last year of life, but its uptake is limited.
• Difficulty in accurately predicting 1-year mortality is a key barrier to timely palliative care initiation in COPD.

Purpose of the Study:

• To develop and validate a novel risk prediction model for 1-year mortality in patients with chronic obstructive pulmonary disease (COPD).
• To assess the performance of the new model against existing mortality prediction tools.
• To identify COPD patients in primary care who could benefit from palliative care interventions.

Main Methods:

• Utilized two UK primary care COPD cohorts from electronic healthcare records (Clinical Practice Research Datalink).
• Developed a Cox regression model (BARC index) using training data, incorporating factors like BMI, blood results, age, respiratory variables, and comorbidities.
• Validated the BARC index's predictive performance (calibration and discrimination) in a separate test set and an external dataset, comparing it with BODEx, DOSE, and ADO scores.

Main Results:

• The BARC index demonstrated acceptable predictive performance in both the test set (C-index=0.79) and external dataset (C-index=0.67).
• It accurately predicted the probability of death within 1 year, with observed and expected probabilities closely aligned across risk quartiles.
• BARC significantly outperformed existing scores (BODEx, DOSE, ADO) in predicting 1-year mortality, particularly when specialist respiratory variables were unavailable.

Conclusions:

• The BARC index is a superior tool for predicting 1-year mortality in COPD patients compared to current methods.
• Its reliance on routinely collected, non-specialist data makes it highly applicable in primary care settings.
• The BARC index can facilitate the identification of COPD patients eligible for and likely to benefit from palliative care.