Some in-scope ambulatory surgeries (i.e., in-scope “narrow” surgeries that were started in the emergency department) may be over- or under-represented in the 2022 Nationwide Ambulatory Surgery Sample (NASS) due to about 3,000 records missing from the State Ambulatory Surgery Database (SASD) in one Western state. The impact of omitting these records from the NASS’s 9,097,088 sampled encounters will vary by ambulatory surgery. Most notably, the 2022 NASS will underestimate the number of appendectomies by about 0.5 percent nationally and by 2.6 percent in the West.

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