BACKGROUND: Helicobacter pylori (Hp) infection has been well-established as a significant risk factor for several gastrointestinal disorders. The urea breath test (UBT) has emerged as a leading non-invasive method for detecting Hp. Despite numerous studies confirming its substantial accuracy, the reliability of UBT results is often compromised by inherent limitations. These findings underscore the need for a rigorous statistical synthesis to clarify and reconcile the diagnostic accuracy of the UBT for the diagnosis of Hp infection.
AIM: To determine and compare the diagnostic accuracy of ¹³C-UBT and ¹⁴C-UBT for Hp infection in adult patients with dyspepsia.
METHODS: We conducted an independent search of the PubMed, Embase, and Cochrane Central databases until April 2022. Our search included diagnostic accuracy studies that evaluated at least one of the index tests (¹³C-UBT or ¹⁴C-UBT) against a reference standard. We used the QUADAS-2 tool to assess the methodological quality of the studies. We utilized the bivariate random-effects model to calculate sensitivity, specificity, positive and negative test likelihood ratios (LR+ and LR-), as well as the diagnostic odds ratio (DOR), along with their 95% confidence intervals. We conducted subgroup analyses based on urea dosing, time after urea administration, and assessment technique. To investigate a possible threshold effect, we conducted Spearman correlation analysis, and we generated summary receiver operating characteristic (SROC) curves to assess heterogeneity. Finally, we visually inspected a funnel plot and used Egger’s test to evaluate publication bias.
RESULTS: The titles and abstracts of 4,621 studies were screened; 79 articles were retrieved and selected for full-text reading. Finally, 60 studies were included in the diagnostic test accuracy meta-analysis. Our analysis demonstrates superior diagnostic accuracy of ¹³C-UBT over ¹⁴C-UBT, indicated by higher sensitivity (96.60% vs. 96.15%), specificity (96.93% vs. 89.84%), likelihood ratios (LR+ 22.00 vs. 10.10; LR- 0.05 vs. 0.06), and AUC (0.979 vs. 0.968). Notably, ¹³C-UBT's DOR (586.47) significantly outperforms ¹⁴C-UBT (DOR 226.50), making it the preferred diagnostic tool for Hp infection. Correlation analysis revealed no threshold effect (¹³C-UBT r = 0.48; ¹⁴C-UBT r = -0.01), and SROC curves showed consistent accuracy. Both ¹³C-UBT and ¹⁴C-UBT showed high AUC values (¹³C-UBT 0.979; ¹⁴C-UBT 0.968) near 1.00. Our research also indicates that urea dose, assessment timing, and measurement technique can also impact test accuracy.
CONCLUSION: Our study has demonstrated that ¹³C-UBT outperforms the ¹⁴C-UBT and ought to be the preferred diagnostic approach. Additionally, our results emphasize the significance of carefully considering urea dosage, assessment timing, and measurement techniques for both tests, in order to enhance diagnostic precision.

<b>Figure 1.</b> Summary operating characteristics curve (SROC) curve for studies based on the <sup>13</sup>C-UBT for <i>H. pylori </i>infection in dyspeptic patients.

Figure 1. Summary operating characteristics curve (SROC) curve for studies based on the ¹³C-UBT for H. pylori infection in dyspeptic patients.

<b>Figure 2. </b>Summary operating characteristics curve (SROC) curve for studies based on the<sup> 14</sup>C-UBT for <i>H. pylori</i> infection in dyspeptic patients.

Figure 2. Summary operating characteristics curve (SROC) curve for studies based on the¹⁴C-UBT for H. pylori infection in dyspeptic patients.

Cláudio Lima Souza

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