Reply to Zhai and Bi

We would like to thank Drs. Zhai and Bi for their interest and comments regarding our recent publication “Gastric peroral endoscopic pyloromyotomy versus gastric electrical stimulation in the treatment of refractory gastroparesis: a propensity score-matched analysis of long-term outcomes” [1].

First, Drs. Zhai and Bi mentioned that our reporting of propensity score analysis is not standardized. As we described in our method section, we used logistic regression including seven variables to estimate the propensity score and matched patients using a one-to-one nearest neighbor caliper of width 0.1 without replacement. We totally agree with them that the small number of events per variable in our study may lead to a biased propensity score and impaired power. As a retrospective study, it was susceptible to selection bias. We selected as many variables (seven) as possible to estimate the propensity score and reduce the selection bias. We agree that a table containing the characteristics before and after propensity score matching would be useful and are happy to provide this (Table 1s, see online-only Supplementary Material).

Second, we respectfully disagree. As this is a novel clinical study, we are all trying to provide as much information as possible and hopefully this will form a foundation for future studies.

Third, our figure 5 illustrates the mean change from baseline in the two scores at seven time points. The mean value at each time point was compared between the two groups using Student’s t test. As we pointed out, 10 % (12/111) of patients with incomplete data, mainly due to lack of follow-up information, were excluded.

Publication History

Article published online:
28 July 2020

• References

• 1 Shen S, Luo H, Vachaparambil C. et al. Gastric peroral endoscopic pyloromyotomy versus gastric electrical stimulation in the treatment of refractory gastroparesis: a propensity score-matched analysis of long term outcomes. Endoscopy 2020; 52: 349-358