Letters to the Editor
To the Editor:
We read with interest the article by Prieto-Jimenez et al (1); however, the conclusion overlooks the problem of adherence to treatment. A success rate of 44% has never been reported since dual therapies were introduced or in more recent pediatric trials. Compliance is the most important factor predicting treatment success (2), and eradication rates of 20% were reported in those taking <60% of pills (3).
In the El Paso children, several indicators of poor adherence are present: treatment of asymptomatic disease, side effects/bad taste of medication, patient's lack of belief in the benefits of treatment and of insight into the illness, complexity of treatment and possibility of receiving placebo, patients not asking for medical advice, and low income (4).
That compliance was suboptimal is confirmed by a second article on the same cohort aiming at assessing iron stores after Helicobacter pylori treatment (5). How do the authors explain that after 6 months of iron administration, ferritin levels only showed a minimal increase after H pylori eradication? A similar experience revealed that in 2 months, children who received iron plus eradication doubled their ferritin content. (6) Perhaps, as in the case of antibiotics, they were poorly adherent to iron therapy. We have employed the sequential regimen to treat >200 children with an eradication rate >85% (7). Our data have been confirmed by a recent meta-analysis (eradication rate of 90.7%; 95% confidence interval 83.8%–94.9%) (8).
Adherence is a primary determinant of treatment efficacy. When treatment outcome is markedly lower than expected, the key to the reading may well be the question “how often do you fail to take all your medication?”
1. Prieto-Jimenez CA, Cardenas VM, Fischbach LA, et al. Double-blind randomized trial of quadruple sequential Helicobacter pylori
eradication therapy in asymptomatic infected children in El Paso, Texas. J Pediatr Gastroenterol Nutr
2. Graham D, Lew GM, Malaty HM, et al. Factors influencing the eradication of Helicobacter pylori
with triple therapy. Gastroenterology
3. Wermeille J, Dederding JP, Cunningham M, et al. Failure of Helicobacter pylori
eradication in an ambulatory population: is poor compliance the main cause? Digestion
1998; 59 (suppl 3):437.
4. Osterberg L, Blaschke T. Adherence to medication. N Engl J Med
5. Cardenas VM, Prieto-Jimenez CA, Mulla ZD, et al. Helicobacter pylori
eradication and change in markers of iron stores among non-iron-deficient children in El Paso, Texas: an etiologic intervention study. J Pediatr Gastroenterol Nutr
6. Choe YH, Kim SK, Son BK, et al. Randomized placebo-controlled trial of Helicobacter pylori eradication for iron-deficiency anemia in preadolescent children and adolescents. Helicobacter
7. Francavilla R, Lionetti E, Cavallo L. Sequential treatment for Helicobacter pylori
eradication in children. Gut
8. Gatta L, Vakil N, Leandro G, et al. Sequential therapy or triple therapy for Helicobacter pylori
infection: systematic review and meta-analysis of randomized controlled trials in adults and children. Am J Gastroenterol