Abstract Rationale The diagnosis of Primary ciliary dyskinesia (PCD) is usually made by a composite reference standard. There are limited data on the utility of the PCD predictive tool, PrImary CiliARy DyskinesiA Rule (PICADAR) in a developing country. The score may help in early diagnosis, which would result in a better outcome. This study aimed to evaluate the performance of the PICADAR score for predicting PCD in children from India. Methods This prospective study included suspected cases of PCD having unexplained persistent wet cough. The study recorded clinical features, including PICADAR score, and various tests, including nasal NO, high-speed video microscopy (HSVM), TEM, and whole exome sequencing (WES). We established the diagnosis of PCD by composite reference standard and considered four categories: (1) confirmed PCD, (2) probable PCD, (3) not PCD, and (4) inconclusive. The primary outcome measure was the predictive values of the PICADAR score as per the already reported cut-off. The secondary outcome measure was the best cut-off value in our study. We evaluated the outcomes in both total (confirmed plus probable) and confirmed PCD cases. Results Among 216 patients enrolled, 62 (28.7%), 42 (19.4%), 53 (24.5%), and 59 (27.3%) were confirmed, probable, not PCD, and inconclusive, respectively. We excluded inconclusive cases. The median (IQR) age at presentation was 9 (6, 12) years, and 57.3% were males. The overall median (IQR) PICADAR score was 4 (3, 7) with a range of 1 to 14. The PICADAR score was 6 (4, 8) and 7 (4, 9) in total and confirmed PCD cases, respectively; the score was significantly higher than in no PCD cases 2 (2, 3), p values 0.001. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) with 95% CI of PICADAR score ≥ 5 were 66.3% (56.4, 75.3), 96.2% (87.0, 99.5), 97.2% (90.2, 99.7), and 59.3% (48.2, 69.8), respectively, for total PCD cases. It was 72.6% (59.8, 83.1), 96.2% (87, 99.5), 95.7% (85.5, 99.5), 75% (63, 84.7), respectively for confirmed cases. The area under the ROC curve was 0.88 (95% CI 0.83, 0.93) and 0.90 (95% CI 0.85, 0.96) for total and confirmed PCD cases, respectively (Figure 1). The Youden index was best for the PICADAR cut-off of ≥ 5 for both total and confirmed PCD cases. Conclusion The PICADAR score ≥ 5 predicted PCD well from India also, though the sensitivity was lower in our cohort compared to reported previously. This abstract is funded by: ICMR, DBT India
Jat et al. (Fri,) studied this question.