PredictIng the risk for first COPD severe exacerbation (PRECISE-X)

Study type

• Study type:
  Not applicable

Population studied

• Age groups:
  Adults (18 to < 46 years)

  Adults (46 to < 65 years)

  Adults (65 to < 75 years)

  Adults (75 to < 85 years)

  Adults (85 years and over)
• Estimated number of subjects:
  0

Study design details

• Main study objective:
  Observational retrospective database study investigating risk factors for the first severe COPD exacerbation since COPD diagnosis (endpoint 5years), using commonly recorded variables.
• Outcomes:
  1. Identification of the risk factors leading to the first severe COPD-related exacerbation within 5 years of COPD diagnosis. 2. Risk of experiencing ≥1 COPD-related exacerbations. 1. Annualised rate of severe COPD exacerbations. 2. Time of occurrence of severe COPD exacerbations.
• Data analysis plan:
  The study will use an accelerated failure time (AFT) model for prediction. AFT models are flexible survival models that enable the full specification of survival time (unlike the Cox proportional hazard model that leaves baseline hazard unspecified), this enabling prediction of time to the event of interest as well as the cumulative hazard of the event, which can be turned into an estimate of 5-year risk through the relation P(event)=1-exp(-H(t)) where H(t) is the cumulative hazard at time t. For model validation, the study will assess model calibration by drawing the calibration plots and evaluating calibration slope (A) and intercept (B). The model discrimination will be calculated via Receiver Operating Characteristic (ROC) curve analysis and evaluating the Area Under the Curve (AUC), equal to the c-statistic. Finally, the potential clinical utility of the model via Decision Curve Analysis (DCA) will be also analysed and calculated accordingly.