Table 4.
Patient characteristics associated with kidney stone events among those with PHPT based on IPW-adjusteda multivariable Cox proportional hazards regression after excluding patients who underwent delayed parathyroidectomy (> 2 y after PHPT diagnosis)
| Patients with kidney stone history (n = 5315) | Patients without kidney stone history (n = 37 336) | |||
|---|---|---|---|---|
| Adjusted HR | 95% CI | Adjusted HR | 95% CI | |
| Parathyroidectomy | 2.14 | 1.67-2.74 | 1.31 | 0.87-1.98 |
| Parathyroidectomy time, y | 0.81 | 0.75-0.88 | 0.95 | 0.89-1.02 |
| Age, y | ||||
| < 35 | Referent | Referent | ||
| 35-49 | 0.77 | 0.45-1.30 | 0.76 | 0.43-1.34 |
| 50-64 | 0.64 | 0.39-1.06 | 0.94 | 0.54-1.63 |
| 65-74 | 0.42 | 0.25-0.70 | 0.56 | 0.31-1.01 |
| 75+ | 0.31 | 0.17-0.58 | 0.41 | 0.22-0.77 |
| Male | 0.96 | 0.73-1.26 | 1.46 | 1.00-2.11 |
| Race | ||||
| White | Referent | Referent | ||
| American Indian or Alaska Native | 1.37 | 0.63-2.98 | 0.94 | 0.39-2.26 |
| Asian | 1.24 | 0.39-3.95 | 0.94 | 0.32-2.80 |
| Black or African American | 1 | 0.77-1.29 | 0.79 | 0.55-1.13 |
| Native Hawaiian or Other Pacific Islander | 1.15 | 0.53-2.52 | 0.97 | 0.40-2.35 |
| Unknown | 1.01 | 0.60-1.69 | 0.71 | 0.50-1.03 |
| Ethnicity | ||||
| Not Hispanic or Latino | Referent | Referent | ||
| Hispanic or Latino | 1.11 | 0.79-1.56 | 0.99 | 0.66-1.48 |
| Unknown | 0.95 | 0.47-1.94 | 0.91 | 0.47-1.77 |
| Charlson Comorbidity Index | ||||
| 0 | Referent | Referent | ||
| 1 | 0.97 | 0.73-1.29 | 0.99 | 0.65-1.51 |
| 2+ | 0.97 | 0.75-1.25 | 0.97 | 0.69-1.35 |
| Calcium ≥ 11.3 mg/dL | 1.27 | 1.05-1.55 | 1.32 | 1.02-1.70 |
| Osteoporosis | 0.99 | 0.72-1.36 | 0.98 | 0.69-1.39 |
| eGFR < 60 mL/min/1.73 m2 | 0.99 | 0.78-1.24 | 0.89 | 0.68-1.15 |
| Diabetes | 0.97 | 0.68-1.40 | 0.72 | 0.47-1.10 |
| Hypertension | 0.9 | 0.70-1.15 | 1.05 | 0.75-1.47 |
| Gout | 0.87 | 0.60-1.24 | 1 | 0.57-1.75 |
| Urinary calcium, mg | ||||
| <400 | Referent | Referent | ||
| ≥ 400 | 0.81 | 0.61-1.06 | 1.08 | 0.76-1.54 |
| Missing | 0.9 | 0.75-1.09 | 0.98 | 0.73-1.30 |
| BMI | ||||
| Underweight | Referent | Referent | ||
| Normal weight | 1.64 | 0.55-4.88 | 1.14 | 0.45-2.88 |
| Overweight | 1.52 | 0.52-4.49 | 0.94 | 0.38-2.31 |
| Obese | 1.64 | 0.56-4.80 | 1.14 | 0.45-2.86 |
| Severely obese | 1.52 | 0.50-4.63 | 1.75 | 0.62-4.91 |
| Unknown | 1.65 | 0.44-6.20 | 1.39 | 0.47-4.08 |
| Stone history | ||||
| Diagnosis | Referent | |||
| Clinically significant event | 2.1 | 1.70-2.58 | ||
| Nephrologist/urologist visit | 1.97 | 1.55-2.50 | 1.4 | 1.03-1.89 |
| Endocrinologist visit | 1.07 | 0.85-1.36 | 1.7 | 1.25-2.33 |
Abbreviations: BMI, body mass index; eGFR, estimated glomerular filtration rate; HR, hazard ratio; IPW, inverse probability weighting; PHPT, primary hyperparathyroidism.
a The propensity score used for IPW in this table was based on all variables in this table (excluding interaction terms).