Trends in Pelvic Inflammatory Disease Among American Indian and Alaska Native Women, Indian Health Service, 2001-2015.

OBJECTIVES: To describe trends in rates of pelvic inflammatory disease (PID) encounters among American Indian/Alaska Native (AI/AN) women aged 15 to 44 years in the United States receiving care within the Indian Health Service (IHS). METHODS: We analyzed IHS discharge data sets for PID encounters during 2001 to 2015 with International Classification of Diseases, Ninth Revision, Clinical Modification, diagnosis codes. We calculated rates of PID encounters per 100 000 women overall and stratified by age group, region, and health care setting. We used regression to identify trends in the total, annual, and average annual percent changes in the rate of PID encounters. RESULTS: There were 44 042 PID encounters during 2001 to 2015 (rate = 825 per 100 000). The highest rates were among women aged 20 to 24 years (1104) and from the Alaska region (1556). Rates significantly decreased overall (2001: 1084; 2015: 512; P < .001) and within all age groups and health care settings. There was variability in Alaska, with large increases during 2001 to 2010 followed by large decreases during 2010 to 2015. CONCLUSIONS: We observed decreasing trends in PID encounters among AI/AN women aged 15 to 44 years during 2001 to 2015, with the exception of increases in the Alaska region.