{
  "abstract": "Introduction Six-minute walk test (6MWT) derived parameters are widely used to assess prognosis in interstitial lung disease (ILD). While exercise induced desaturation and six-minute walk distance (6MWD) are established predictors of outcome, the prognostic value of oxygen saturation (SpO 2) recovery time post 6MWT in ILD is not well established.Method 6MWT data were retrospectively analysed from 313 ILD patients who performed a 6MWT between 2023 and 2024. We evaluated the ability of several 6MWT derived parameters to predict 1-year and 2-year mortality and lung transplantation. Variables included minimum SpO 2, 6MWD, SpO2 recovery time (defined as seconds required for SpO2 to recover to within 2% of baseline) and distance saturation product (DSPree; 6MWD × minimum SpO2). Discriminative performance was assessed using the area under the curve (AUC) using receiver operating characteristic curve analysis with sensitivity and specificity. De-long test was used to compare difference in AUC between 6MWT parameters. Optimal SpO2 recovery thresholds were identified for 1- and 2-year outcomes. Survival and transplantation outcomes were analysed using Kaplan Meier with log-rank testing.Results The discriminative performance of 6MWT parameters are shown in table 1. For 1-year mortality, SpO 2 recovery time demonstrated the highest discrimination (AUC 0.75, 95% CI 0.67–0.83) with high sensitivity (89%) and significantly greater discriminative ability than minimum SpO2 (AUC 0.67, 95% CI 0.57–0.76; p=0.028). DSP (AUC 0.74) and 6MWD (AUC 0.73) showed comparable performance. For 2-year mortality, DSP and SpO2 recovery performed similarly well (AUC 0.73, 0.72 respectively). DSP demonstrated high sensitivity (80%), whereas SpO2 recovery showed balanced sensitivity (72%) and specificity (64%). Minimum SpO2 and 6MWD demonstrated slightly lower performance (AUC 0.69, 0,70 respectively). Optimal SpO2 recovery thresholds associated with increased risk were ≥97.5 seconds at 1 year and ≥109 seconds at 2 years, with significant differences in survival and transplantation free survival across both thresholds (log-rank p<0.001).Conclusion SpO 2 recovery following the 6MWT demonstrated good sensitivity and overall prognostic discrimination for 1- and 2-year outcomes in ILD. Compared with minimum SpO2, SpO2 recovery showed superior sensitivity and may provide complementary prognostic information beyond traditional 6MWT parameters. Incorporation into future composite 6MWT prognostic scores warrants further evaluation.Abstract O1 Table 1Discriminative performance of 6MWT parameters to predict 1 and 2 year outcomes",
  "authors": [
    {
      "affiliations": [
        "Royal Papworth Hospital, Cambridge, United Kingdom"
      ],
      "name": "Lucy Robertson"
    },
    {
      "affiliations": [
        "Royal Papworth Hospital, Cambridge, United Kingdom"
      ],
      "name": "Helen Parfrey"
    },
    {
      "affiliations": [
        "Royal Papworth Hospital, Cambridge, United Kingdom"
      ],
      "name": "Gauri Saini"
    },
    {
      "affiliations": [
        "Royal Papworth Hospital, Cambridge, United Kingdom"
      ],
      "name": "Muhunthan Thillai"
    },
    {
      "affiliations": [
        "Royal Papworth Hospital, Cambridge, United Kingdom"
      ],
      "name": "Nicola Simler"
    },
    {
      "affiliations": [
        "Royal Papworth Hospital, Cambridge, United Kingdom"
      ],
      "name": "Benjamin Knox-Brown"
    }
  ],
  "title": "O1 The prognostic value of oxygen saturation recovery time post 6MWT in interstitial lung disease",
  "uid": "f4fc96dc-f4d9-5086-904d-e58c7250935e"
}