Skip to main content
. 2021 Jan 25;21:97. doi: 10.1186/s12885-021-07790-z

Table 2.

Select characteristics of new users of palbociclib-fulvestrant and new users of fulvestrant monotherapy (historical comparator group) before and after propensity score matching

Characteristicsa Before Propensity Score Matching After Propensity Score Matchingb
New users of palbociclib-fulvestrant New users of fulvestrant monotherapy (pre-2015) Std. difference New users of palbociclib-fulvestrant New users of fulvestrant monotherapy (pre-2015) Std. difference
N/Mean %/SD N/Mean %/SD N/Mean %/SD N/Mean %/SD
Overall 566 100% 2316 100% 561 100% 561 100%
Total duration of follow-up (in years) 324 1686 322 373
Demographics
 Age at index date (in years) 59.3 11.0 64.1 12.9 0.4 59.5 11.0 59.9 13.3 0.04
 Sex
  Male ≤10 n/a 30 1.30 0.0 ≤10 n/a ≤10 n/a 0.10
  Female 557 98.4 2286 98.7 0.0 552 98.4 558 99.5 0.10
 Geographic region of residence
  Midwest 95 16.8 422 18.2 0.04 95 16.9 93 16.6 0.01
  South 159 28.1 690 29.8 0.04 157 28.0 165 29.4 0.03
  Northeast 166 29.3 580 25.0 0.10 164 29.2 158 28.2 0.02
  West 146 25.8 624 26.9 0.03 145 25.8 145 25.8 0.00
Medical History
 Other primary cancer prior to first breast cancer diagnosis code 223 39.4 1026 44.3 0.1 222 39.6 271 48.3 0.18
 Secondary malignancy (metastasis) 496 87.6 1823 78.7 0.2 491 87.5 488 87.0 0.02
  Lymph nodes of head, face, and neck 154 27.2 476 20.6 0.2 151 26.9 150 26.7 0.00
  Respiratory and digestive systems 257 45.4 781 33.7 0.2 254 45.3 252 44.9 0.01
  Other specified sites 463 81.8 1710 73.8 0.2 458 81.6 458 81.6 0.00
 Deyo-Charlson comorbidity index (DCI) without cancer codes 8.5 1.8 7.85 2.3 0.3 8.5 1.8 8.56 1.6 0.03
Cancer Therapy History
 Radiation therapy 112 19.8 386 16.7 0.1 112 20.0 117 20.9 0.02
 Surgery 11 1.9 68 2.9 0.1 11 2.0 13 2.3 0.02
 Chemotherapy 100 17.7 429 18.5 0.0 99 17.6 98 17.5 0.00
 Imaging
  CT related imaging in the last 6 months 139 24.6 501 21.6 0.1 138 24.6 146 26.0 0.03
  Diagnostic imaging in the last 6 months 72 12.7 461 19.9 0.2 72 12.8 79 14.1 0.04
  MRI related imaging 25 4.4 91 3.9 0.0 25 4.5 26 4.6 0.01
Healthcare Utilization (6 months prior to index date)
 Number of outpatient visits 37.6 21.7 36.5 24.6 0.0 37.7 21.8 39.3 24.2 0.07
 Number of inpatient hospitalizations 0.3 0.7 0.3 0.7 0.0 0.3 0.7 0.4 0.8 0.14
 Number of emergency department visits 0.3 0.8 0.2 0.6 0.1 0.3 0.8 0.3 0.7 0.03
Medication Use (breast cancer related)
 Palbociclib 0 0.00 0 0.00 n/a 0 0.00 0 0.00 n/a
 Aromatase inhibitor 326 57.6 1285 55.5 0.04 321 57.2 303 54.0 0.06
  Letrozole 116 20.5 429 18.5 0.05 113 20.1 116 20.7 0.01
  Anastrazole 136 24.0 611 26.4 0.05 135 24.1 138 24.6 0.01
  Exemestane 86 15.2 358 15.5 0.01 85 15.2 76 13.5 0.05
 HER2 positive therapy 15 2.7 127 5.5 0.14 15 2.7 14 2.5 0.01
  Trastuzumab 25 4.4 159 6.9 0.11 24 4.3 27 4.8 0.03
  Lapatinib ≤10 n/a 16 0.7 0.05 ≤10 n/a ≤10 n/a 0.03
  Ado-trastuzumab 0 0.0 0 0.0 n/a 0 0.0 0 0.0 n/a
  Pertuzumab 0 0.0 0 0.0 n/a 0 0.0 0 0.0 n/a
 Tamoxifen 140 24.7 379 16.4 0.21 140 25.0 135 24.1 0.02
 Fulvestrant 238 42.0 0 0.0 n/a 236 42.1 0 0.0 n/a
 Denosumab or Pamidronate 206 36.4 424 18.3 0.41 201 35.8 197 35.1 0.01
 Everolimus 40 7.1 84 3.6 0.15 39 7.0 37 6.6 0.01
Medication Use (not breast cancer related)
 Anticonvulsants 126 22.3 347 15.0 0.19 122 21.7 123 21.9 0.00
 Antidepressants 178 31.4 631 27.2 0.09 175 31.2 184 32.8 0.03
 Antihypertensives 173 30.6 623 26.9 0.08 171 30.5 135 24.1 0.14
 Antimycobacterials 109 19.3 446 19.3 0.00 107 19.1 117 20.9 0.04
 Antivirals 32 5.7 112 4.8 0.04 32 5.7 30 5.3 0.02
 Corticosteroids 148 26.1 416 18.0 0.20 146 26.0 146 26.0 0.00
 Lipid lowering agent 132 23.3 556 24.0 0.02 130 23.2 121 21.6 0.04
 Sedatives/hypnotics 57 10.1 291 12.6 0.08 57 10.2 63 11.2 0.03
Co-morbidities (6 months prior to index date)
 Pathologic fracture 46 8.1 173 7.5 0.02 46 8.2 51 9.1 0.03
 Major adverse cardiac events (MACE) 20 3.5 83 3.6 0.00 20 3.6 23 4.1 0.03
 Cerebrovascular disease 301 53.2 1148 49.6 0.07 296 52.8 277 49.4 0.07
 Hyperglycemia 27 4.8 55 2.4 0.13 23 4.1 29 5.2 0.05
Deyo-Charlson Index (DCI)
  0–3 19 3.4 259 11.2 0.30 19 3.4 17 3.0 0.02
  4–7 12 2.1 57 2.5 0.02 12 2.1 4 0.7 0.12
  8–11 512 90.5 1937 83.6 0.20 508 90.6 517 92.2 0.06
  12 or more 23 4.1 63 2.7 0.07 22 3.9 23 4.1 0.01
Risk factors associated with ALI
 Chronic liver disease or Alcoholismc 74 13.1 246 10.6 0.09 74 13.1 69 12.2 0.03
 Chronic or acute disease of gallbladder or pancreasc 36 6.4 145 6.3 0.01 36 6.4 34 6.0 0.01
 Hepatic, Biliary or pancreatic cancerc 160 28.3 458 19.8 0.18 160 28.3 143 25.3 0.07
 Congestive heart failurec 29 5.1 159 6.9 0.07 29 5.1 29 5.1 0.00
 Any medication associated with liver failurec 467 82.51 1749 75.52 0.17 466 82.48 466 82.48 0.00
 Acetaminophen (prescription) c 204 36.04 899 38.82 0.06 204 36.11 202 35.75 0.01

Abbreviations: ER estrogen receptor, HER2 human epidermal growth factor receptor 2, N number, SD standard deviation, Std standardized, CT computed tomography, MRI magnetic resonance imaging

aAll characteristics are measured as presence within 6 months prior to the index date, unless otherwise specified

bThe following variables were included in the propensity score for all safety event analyses: age, region, Deyo-Charlson Index, number of outpatient visits, number of emergency room visits, secondary malignancy to lymph nodes of head, face, and neck, secondary malignancy to other specified sites, secondary malignancy to respiratory sites, tamoxifen, everolimus, anastrazole, denosumab or pamidronate, exemestane, chemotherapy, corticosteroids, diagnostic imaging, breast cancer surgery, letrozole, HER2 positive therapy, radiation therapy, CT imaging, mammography, MRI imaging, anticonvulsants, antidepressants, sedatives/hypnotics, secondary malignancy to breast, breast cancer diagnosis code, in situ breast cancer diagnosis, hyperglycemia, and cerebrovascular disease

cThe following variables were included in the propensity score specific for subsequent ALI analyses (conducted after observing an association with ALI in initial analyses): age, region, Deyo-Charlson Index, number of outpatient visits, number of emergency room visits, secondary malignancy to lymph nodes of head, face, and neck, secondary malignancy to other specified sites, secondary malignancy to respiratory sites, tamoxifen, everolimus, anastrazole, denosumab or pamidronate, exemestane, chemotherapy, corticosteroids, diagnostic imaging, breast cancer surgery, letrozole, HER2 positive therapy, radiation therapy, CT imaging, mammography, MRI imaging, anticonvulsants, antidepressants, sedatives/hypnotics, secondary malignancy to breast, breast cancer diagnosis code, in situ breast cancer diagnosis, hyperglycemia, cerebrovascular disease, Chronic liver disease or Alcoholism, Chronic or acute disease of gallbladder or pancreas, Hepatic, Biliary or pancreatic cancer, Congestive heart failure, any medication associated with ALI- Acetaminophen, Allopurinol, Amiodarone, Amitriptyline, + clavulanic acid, Aripiprazole, Baclofen, Ciprofloxacin, Clindamycin, Clopidogrel, Duloxetine, Estrogens, Fluoxetine, Ketoconazole, Lisinopril, Losartan, Mirtazapine, Nitrofurantoin, NSAIDs, Omeprazole, Paroxetine, Phenothiazine, Sertraline, Statins, Tetracycline, Trazodone, and Trimethoprim