Evaluation of screening tools for primary ciliary dyskinesia in Egypt: single center study

Abstract

Background: Primary ciliary dyskinesia (PCD) is a chronic respiratory illness that places significant strain on the healthcare system due to the complexity and expense of its diagnosis and treatment methods. The diagnostic process typically requires skilled technicians and an assortment of intricate, costly, and time-consuming approaches. Implementing screening tools can enhance efficiency by focusing the diagnostic process on those strongly suspected of having PCD. Tools such as the PCD Rule (PICADAR), North America Criteria Defined Clinical Features (NA-CDCF), the Clinical Index Score (CI), and the newly proposed CInew13 could potentially serve as useful screening tools. This study aims to examine the effectiveness of these tools individually, compare their performance against each other, and assess their results relative to prior research.

Methods: We conducted a diagnostic accuracy test on 83 Egyptian patients referred to Alexandria University Children's Hospital for potential PCD diagnosis between January 2015 and December 2022. The scores obtained from the screening tools were calculated and assessed.

Results: Of the initial group, 10 patients were ruled out because they fit other diagnostic parameters. Forty-three cases received a confirmed diagnosis, while 30 did not. Notably, the confirmed cases consistently scored higher on our screening tools than those that remained unconfirmed (p <.001, for all tested scores). We used receiver operating characteristic curves to assess and compare the effectiveness of each tool. The NA-CDCF had the smallest area under curve 0.736 (95% confiedence interval 0.619-0.832); in contrast, the CI score had the largest 0.898 (95% confidence interval 0.808-0.957).

Conclusion: All the tools tested were effective in identifying suitable patients for PCD testing at statistically significant levels. However, the PICADAR and NA-CDCF scores' performance did not significantly differ in the current study. The CI and CInew13 scores, on the other hand, outperformed both.

Figure 1

ROC curves for the PICADAR, NA-CDCF, CI, and CI_new13 scores to discriminate between the confirmed and the non-confirmed cases.

Figure 2

Venn diagram for the tested screening tools. When applying the originally proposed cut-offs, 52 PCD patients tested positive with the four screening tools, while 11 had positive results with the PICADAR, NA-CDCF, and CI_new13 but not the CI score. Three patients had positive results with the NA-CDCF, CI, and CI_new13 but not with PICADAR. Another 3 patients tested positive for PICADAR and NA-CDCF but neither CI nor CI_new13.

Figure 3

Box and whisker graph of the different screening tools (a: PICADAR, b: NA-CDCF, c: CI score, and d: CI_new13) in the studied group. The thick line in the middle of the box represents the median, the box represents the inter-quartile range (from 25^th to 75^th percentiles), and the whiskers represent the minimum and maximum after excluding outliers (circles). The horizontal red line represents the original cut-off value, while the horizontal blue line represents the cut-off with the best performance among the study cohort.

Figure 3

Box and whisker graph of the different screening tools (a: PICADAR, b: NA-CDCF, c: CI score, and d: CI_new13) in the studied group. The thick line in the middle of the box represents the median, the box represents the inter-quartile range (from 25^th to 75^th percentiles), and the whiskers represent the minimum and maximum after excluding outliers (circles). The horizontal red line represents the original cut-off value, while the horizontal blue line represents the cut-off with the best performance among the study cohort.