Study population and study design:
We analyzed NIS data from January 2015 to December 2017. The study
population was selected by using the International Classification of
Diseases, 9th Revision, Clinical Modification (ICD-9-CM) and
International Classification of Diseases, 10th Revision, Clinical
Modification (ICD-10-CM) codes. We selected patients 18 years of age and
above for the purpose of our study. Age was further divided into three
groups, <65, 65-74 and ≥75. Patients implanted with a WATCHMAN
were identified by ICD-9 code of 37.90 and ICD-10 code of 02L73DK.
Baseline characteristics and key complications were identified (ICD
codes for complications provided in supplement), as previously described
(13). Hospital outcomes including in-patient mortality, discharge
disposition, length of stay (LOS) and cost of hospitalization (inflation
adjusted) were derived. For the computation of hospitalization costs,
cost-to-charge ratio files from NIS were utilized.
Complication rate trends were analyzed over the study years. The primary
outcome of the study was the prevalence of Watchman implantation over
our study period. Additional outcomes analyzed including associated
complications, in-hospital mortality and resource utilization (including
LOS, cost of stay and discharge disposition to home, short term care,
long-term care or home with institutional care or home health).