Update: re: Yesterday’s post on tax inversion. NPR report: Pfizer calls off Allergan Merger due to anti-inversion rules instituted by Treasury Dept
“Generally, the clinical course for the majority of gallstones is asymptomatic…Overall, little knowledge exists about the development into symptomatic disease.” This introduction from a recent study (DM Shabanzadeh et al. Gastroenterol 2016; 150: 156-67-thanks to Ben Gold for sharing his interest in this study) provides the rationale for their study which analyzed 3 randomly selected groups in Denmark (ages 30-70 years) and followed them for a median of 17.4 years.
Out of an initial 6037 participants, 664 had gallstones at baseline (after excluding 189 who had cholecystectomy and 5180 without gallstones). Only 10% were aware that they had gallstones.
19.6% developed symptomatic disease (8% complicated, 11.6% uncomplicated)
Risks for symptomatic disease: Female sex, Younger age, Stone size >10 mm, Multiple stones
- Male with small stone: 2/67 (HR 1.0)
- Male with multiple stones: 4/97 (HR 1.83)
- Male with large stone: 2/47 (HR 2.79)
- Male with multiple and large stones: 3/29 (HR 5.12)
- Female with small stone: 4/102 (HR 2.16)
- Female with multiples stones (no large stones) 11/120 (HR 3.96)
- Female with large stone: 12/67 (HR 6.02)
- Highest risk: female with multiple stones and with largest stone >10 mm: 10/53(HR 11.05)
Interestingly, the 10% who knew that they had gallstones before randomly being selected into the study had significantly higher rates of all outcomes, especially uncomplicated events. “This finding may reflect a protopathic bias.” Patients who were aware were more likely to have suffered bilary colic attacks before study entry and thus had a higher risk of events.
My take: First of all, completion of this study over more than 17 years is an astonishing feat, particularly without informing the participants of their gallstone status. In patients who are truly asymptomatic, my interpretation would be that only those at substantial risk would benefit from cholecystectomy. This study does not account for other factors that could favor cholecystectomy (in asymptomatic patients) such as hemolytic diseases (e.g. sickle cell), cystic fibrosis, and other conditions in which symptomatic gallbladder disease is more likely to develop.
Related blog posts: