Table 1.

Select Characteristics of New Users of Palbociclib Identified in the HIRD

Characteristicsa	All new users of palbociclib		New users of palbociclib-fulvestrant		New users of palbociclib-letrozole		All other new users of palbociclib
	N/Mean	%/SD	N/Mean	%/SD	N/Mean	%/SD	N/Mean	%/SD
Overall	2445	100%	566	100%	1159	100%	720	100%
Total duration of follow-up of cohort (in years)	1540		324		812		404
Duration of follow-up (in years)	0.63	0.53	0.57	0.43	0.70	0.58	0.56	0.50
Age at index date (in years)	59.79	11.62	59.47	11.38	59.21	11.27	60.95	12.29
Sex
Male	53	2.17	< 10	n/a	14	1.21	30	4.17
Female	2392	97.83	557	98.41	1145	98.79	690	95.83
Calendar year of index date
2015	791	32.35	99	17.49	456	39.34	236	32.78
2016	942	38.53	269	47.53	406	35.03	267	37.08
2017	712	29.12	198	34.98	297	25.63	217	30.14
Geographic region of residence
Midwest	400	16.36	95	16.78	185	15.96	120	16.67
South	581	23.76	159	28.09	288	24.85	134	18.61
Northeast	696	28.47	166	29.33	340	29.34	190	26.39
West	768	31.41	146	25.80	346	29.85	276	38.33
Secondary malignancy to any site (metastasis)	2137	87.40	496	87.63	1044	90.08	597	82.92
Secondary malignancy to Lymph nodes of head, face, and neck metastasis	690	28.22	154	27.20	356	30.72	180	25.00
Secondary malignancy to Respiratory and digestive system metastasis (includes liver metastasis)	1058	43.27	257	45.41	490	42.28	311	43.19
Secondary malignancy to Metastasis to other specified sites	2017	82.49	463	81.80	978	84.38	576	80.00
Deyo-Charlson comorbidity index (DCI)	8.39	1.90	8.52	1.76	8.48	1.70	8.13	2.25
Advanced stage ER+/HER2- breast cancer	2285	93.46	548	96.82	1083	93.44	654	90.83
Radiation therapy	483	19.75	112	19.79	233	20.10	138	19.17
Chemotherapy	472	19.30	100	17.67	218	18.81	154	21.39
CT related imaging	602	24.62	139	24.56	333	28.73	130	18.06
Number of outpatient visits	39.67	25.20	38.58	23.63	39.51	23.78	40.79	28.42
Aromatase inhibitor	1527	62.45	326	57.60	815	70.32	386	53.61
HER2+ therapy	72	2.94	15	2.65	35	3.02	22	3.06
Tamoxifen	552	22.58	140	24.73	270	23.30	142	19.72
Fulvestrant	621	25.40	238	42.05	112	9.66	271	37.64
Denosumab or pamidronate	836	34.19	206	36.40	359	30.97	271	37.64
Everolimus	150	6.13	40	7.07	52	4.49	58	8.06
Antihypertensives	653	26.71	173	30.57	293	25.28	187	25.97
Corticosteroids	606	24.79	148	26.15	308	26.57	150	20.83
Lipid lowering agent	528	21.60	132	23.32	251	21.66	145	20.14
Pathologic fracture	211	8.63	46	8.13	110	9.49	55	7.64
Pure hypercholesterolemia	215	8.79	48	8.48	105	9.06	62	8.61

Abbreviations: HIRD HealthCore Integrated Research Database, N number, SD standard deviation, ER estrogen receptor, HER2 human epidermal growth factor receptor 2, CT computed tomography

^aAll characteristics are measured as presence within six months prior to palbociclib initiation, unless otherwise specified