Table.

Baseline Characteristics of Study Participants and Adjusted Odds Ratios of Receiving at least One Opioid Prescription Within 60 Days of Discharge After Total Hip or Knee Arthroplasty^a

	THA (n=86,058)					TKA (n=150,573)
Patient Characteristics^a	N	%	OR	95% CI		N	%	OR	95% CI
Year of Surgery
2014	18940	22.01	1.00			35267	23.42	1.00
2015	21692	25.21	1.36	1.29	1.44	38595	25.63	1.42	1.36	1.47
2016	23228	26.99	1.66	1.57	1.75	39485	26.22	1.85	1.77	1.93
2017	22198	25.79	1.92	1.81	2.03	37226	24.72	2.40	2.30	2.52
Level of pain at discharge
0	5247	6.10	1.00			7316	4.86	1.00
1–3	35372	41.10	1.38	1.28	1.49	48270	32.06	1.40	1.31	1.50
4–6	37824	43.95	1.50	1.39	1.62	76599	50.87	1.50	1.40	1.60
7–10	7615	8.85	1.32	1.20	1.46	18388	12.21	1.38	1.28	1.48
Age at THA/TKA admission, mean (SD)	64.48	11.17				65.99	9.59
Age Category
<55	14906	17.32	1.00			17461	11.60	1.00
55–64	27662	32.14	0.88	0.82	0.94	48598	32.28	0.85	0.81	0.91
65–74	26948	31.31	0.74	0.68	0.79	54567	36.24	0.74	0.70	0.79
75+	16542	19.22	0.55	0.51	0.60	29947	19.89	0.57	0.54	0.62
Gender
Female	46684	54.25	1.00			92726	61.58	1.00
Male	39374	45.75	1.06	1.02	1.11	57847	38.42	1.04	1.01	1.07
Race/Ethnicity^b
Caucasian	75604	87.85	1.00			129232	85.83	1.00
African American	6177	7.18	0.79	0.74	0.86	11299	7.50	0.86	0.81	0.92
Hispanic	1660	1.93	0.60	0.53	0.68	4371	2.90	0.53	0.49	0.57
Smoking Status^b,c
Current smoker	13479	15.66	1.00			18178	12.07	1.00
Not currently smoking	37234	43.27	0.86	0.81	0.92	66673	44.28	0.88	0.83	0.92
Never smoked	30762	35.75	1.07	1.01	1.15	57750	38.35	1.23	1.17	1.30
Insurance^b
Commercial/Other (1 insurance)	38640	44.90	1.00			62580	41.56	1.00
Medicare Only	28,622	33.26	1.28	1.21	1.37	52797	35.06	1.28	1.22	1.34
Medicaid Only	3011	3.50	1.29	1.13	1.47	4298	2.85	1.18	1.06	1.32
2 or More Insurances	11465	13.32	0.61	0.57	0.65	23729	15.76	0.56	0.53	0.59
Anxiety	13937	16.19	0.93	0.88	0.99	26086	17.32	1.01	0.97	1.06
Depression	16354	19.00	1.08	1.01	1.14	36101	23.98	0.98	0.94	1.02
Substance Use Disorders	4213	4.90	0.99	0.89	1.09	4979	3.31	0.92	0.85	1.01
Number of Condition Categories, mean (SD)	2.74	2.26	1.05	1.04	1.06	3.12	2.28	1.09	1.08	1.10
Condition Categories^d
Arrhythmia	13348	15.51				25366	16.85
Atherosclerosis	11233	13.05				21281	14.13
Cancer	8744	10.16				15323	10.18
Cellulitis	2391	2.78				4743	3.15
CHF	3506	4.07				6561	4.36
COPD	7530	8.75				12606	8.37
Dementia	1506	1.75				2806	1.86
Diabetes	14116	16.40				34801	23.11
Dialysis	95	0.11				146	0.10
Fluid or metabolic disorder	7246	8.42				12828	8.52
Hemolytic disorder	211	0.25				287	0.19
Hypertension	52116	60.56				103799	68.94
Major symptoms, abnormalities	45451	52.81				86404	57.38
Malnutrition	406	0.47				395	0.26
Metastatic cancer	314	0.36				371	0.25
Morbid obesity	9086	10.56				25868	17.18
Other injuries	11991	13.93				28550	18.96
Paralysis	799	0.93				1300	0.86
Pneumonia	1499	1.74				2706	1.80
Polyneuropathy	8347	9.70				16993	11.29
Psychiatric	4314	5.01				8528	5.66
Renal failure	6993	8.13				13514	8.98
Rheumatoid arthritis	6037	7.02				10428	6.93
Severe infection	7186	8.35				13863	9.21
Stroke	920	1.07				1693	1.12
Ulcer	738	0.86				1219	0.81
Vascular disorder	9261	10.76				16801	11.16

Patients received THA or TKA in 2014–2017 from Optum EHR data which contains structured information, such as diagnosis, procedure codes, lab results and observations, including vital signs, blood pressure, pain and body mass index (BMI). It also contains unstructured information in the form of clinical notes from office visits, consultation reports, discharge summaries and reports from nursing records, pathology, radiology and cardiology. Using a natural language processing (NLP) system, Optum staff extract these unstructured data and organize them into structured fields for clinical assessment. Clinical measurements include numeric fields from clinical notes such as blood pressure, pain and BMI. We identified THA or TKA using ICD-9, ICD-10, or CPT codes (THA: ICD-9, 81.51; ICD-10, 0SR90J9, 0SR90JA, 0SR90JZ, 0SRB0J9, 0SRB0JA, 0SRB0JZ; CPT, 27130; TKA: ICD-9, 81.54; ICD-10, 0SRC07Z, 0SRC0JZ, 0SRC0KZ, 0SRC0LZ, 0SRD07Z, 0SRD0JZ, 0SRDD0KZ, 0SRD0LZ, 0SRT07Z, 0SRT0JZ, 0SRT0KZ, 0SRU07Z, 0SRU0JZ, 0SRU0KZ, 0SRV07Z, 0SRV0JZ, 0SRV0KZ, 0SRW07Z, 0SRW0JZ, 0SRW0KZ; CPT, 27447).

Other or unknown categories were included in the model, but not reported.

Smoking status (never, former, current, other) were obtained from clinical observations found in the EHR and were taken from the observation nearest to the day of discharge, up to 6 months prior to the date of discharge. When there were multiple recorded statuses for smoking or selected, we recorded the most severe category with the “other” category being the least severe (i.e. current smoker, former smoker, never smoker, other).

The number of condition categories were included in the model, not as individual, separate conditions. These condition categories came from the CMS report on hospital readmission for hip or knee arthroplasty and additional conditions, including anxiety, depression, and substance use disorder. All of these condition category variables were assessed in the 12 months prior to the joint arthroplasty.