Gastrointestinal Events Among Patients Initiating Osteoporosis Therapy: A Retrospective Administrative Claims Database Analysis.

PURPOSE: Our purpose was to characterize the occurrence of gastrointestinal (GI) events among women on oral bisphosphonate therapy.

METHODS: This was a retrospective cohort study that used a United States (US) claims database. The study period was from January 1, 2000, to December 31, 2011. The index date was the date of the first oral bisphosphonate (alendronate, ibandronate, or risedronate) prescription and occurred between January 1, 2001, and December 31, 2010. The pre- and post-index periods were the 1-year periods before and after the index date, respectively. The analysis included women with osteoporosis aged ≥55 years at the index date who were naive to all osteoporosis treatments before the index date and were continuously enrolled in the health plan for at least 1 year before and 1 year after the index date. Patients with a diagnosis of malignant neoplasm during the pre- or post-index periods or a diagnosis of Paget disease anytime in the claims history were excluded. The occurrence of GI events (defined as esophagitis; gastroesophageal reflux disease; ulcer, stricture, perforation, or hemorrhage of the esophagus; gastric, duodenal, or peptic ulcer; acute gastritis; duodenitis; GI hemorrhage; nausea/vomiting; or dysphagia) was assessed during the pre-index period and at 3, 6, and 12 months in the post-index period. The rate of GI events was defined as the percentage of patients having at least 1 GI event in each analysis period (ie, pre-index and post-index periods). GI events in the post-index period were also stratified by the presence of GI events in the pre-index period.

FINDINGS: A total of 75,593 women were included in the analysis. The average age at the index date was 64.4 years. Gastroprotective agents were used by 17.9% of patients. Approximately one fourth of patients (26.6%; n = 20,073) had ≥1 GI events in the pre-index period. Approximately the same proportion of patients (28.0%; n = 21,142) experienced GI events in the post-index period. The cumulative rate of GI events during the post-index period was higher among patients who had GI events in the pre-index period (51.2%) than among patients without a GI event in the pre-index period (19.6%).

IMPLICATIONS: Among women with osteoporosis enrolled in a US commercial plan, GI events were common regardless of bisphosphonate use. Approximately one fourth of US women on bisphosphonate therapy experienced GI events within the year after initiation of therapy, and one half of US women with a previous GI event had another event while taking bisphosphonates.