Acute pancreatitis (AP) and chronic pancreatitis (CP) traditionally have been thought to be distinct diseases, but there is evidence that AP can progress to CP. Little is known about the mechanisms of pancreatitis progression. We performed a meta-analysis to quantify the frequency of transition of AP to CP and identify risk factors for progression.

We searched PubMed, Scopus, and Embase for studies of patients with AP who developed CP, published from 1966 through November 2014. Pooled prevalence and 95% confidence intervals (CIs) were calculated for these outcomes, and sensitivity, subgroup, and meta-regression analyses were conducted.

We analyzed 14 studies, which included a total of 8492 patients. The pooled prevalence of recurrent AP was 22% (95% CI, 18%–26%), and the pooled prevalence of CP was 10% (95% CI, 6%–15%). Sensitivity analyses yielded a pooled prevalence of CP of 10% (95% CI, 4%–19%) and 36% (95% CI, 20%–53%) in patients after the first occurrence and recurrent AP, respectively. Subgroup analyses found alcohol use and smoking to be the largest risk factors for the development of CP, with pooled prevalence values of 65% (95% CI, 48%–56%) and 61% (95% CI, 47%–73%), respectively. Meta-regression analysis found that men were more likely than women to transition from AP to CP.

Ten percent of patients with a first episode of AP and 36% of patients with recurrent AP develop CP; the risk is higher among smokers, alcoholics, and men. Prospective clinical studies are needed to study pancreatitis progression.