Validation of ICD-10 hospital discharge diagnosis codes to identify incident and recurrent ischemic stroke from a US integrated healthcare system.

PURPOSE: This study validated incident and recurrent ischemic stroke identified by International Classification of Diseases, Tenth Revision, Clinical Modification (ICD-10) hospital discharge diagnosis codes. METHODS: Using electronic health records (EHR) of adults (≥18 years) receiving care from Kaiser Permanente Southern California with ICD-10 hospital discharge diagnosis codes of ischemic stroke (I63.x, G46.3, and G46.4) between October 2015 and September 2020, we identified 75 patients with both incident and recurrent stroke events (total 150 cases). Two neurologists independently evaluated validity of ICD-10 codes through chart reviews. RESULTS: The positive predictive value (PPV, 95% CI) for incident stroke was 93% (95% CI: 88%, 99%) and the PPV for recurrent stroke was 72% (95% CI: 62%, 82%). The PPV for recurrent stroke improved after applying a gap of 20 days (PPV of 75%; 95% CI: 63%, 87%) or removing hospital admissions related to stroke-related procedures (PPV of 78%; 95% CI: 68%, 88%). CONCLUSION: The ICD-10 hospital discharge diagnosis codes for ischemic stroke showed a high PPV for incident cases, while the PPV for recurrent cases were less optimal. Algorithms to improve the accuracy of ICD-10 codes for recurrent ischemic stroke may be necessary.

Fertility and pregnancy outcomes in primary hyperparathyroidism: Observations from a large insured population.

CONTEXT: Primary hyperparathyroidism (PHPT) has initially been implicated in adverse maternal and neonatal outcomes, while subsequent population studies have failed to show an association. OBJECTIVE: To compare maternal, pregnancy, and neonatal outcomes in patients with and without PHPT. DESIGN: Retrospective matched-cohort study (2005-2020). SETTING: An integrated healthcare delivery system in Southern California. PATIENTS: Women aged 18-44 years were included. Patients with biochemical diagnosis of PHPT were matched 1:3 with eucalcemic controls (non-PHPT). MAIN OUTCOME MEASURES: Achievement of pregnancy, pregnancy outcomes (including rates of abortion, maternal complications), and neonatal outcomes (including hypocalcemia, need for intensive care). RESULTS: The cohort comprised 386 women with PHPT and 1158 age-matched controls. Pregnancy rates between PHPT and control groups were similar (10.6% vs 12.8%). The adjusted rate ratio of pregnancy was 0.89 (95% CI: 0.64-1.24) (PHPT vs non-PHPT). Twenty-nine pregnancies occurred in women with co-existing PHPT and 191 pregnancies occurred in controls, resulting in 23 (79.3%) and 168 (88.0%) live births, respectively (p=0.023). Neonatal outcomes were similar. Live birth rates were similar (86.4%, 80%, 79.2%) for those undergoing parathyroidectomy prior (n=22), during (n=5), or after pregnancy/never (n=24). Among patients who underwent parathyroidectomy during pregnancy, no spontaneous abortions occurred in women entering pregnancy with peak calcium <11.5 mg/dL [2.9 mmol/L]. CONCLUSIONS: We observed no difference in pregnancy rates between women with or without PHPT. Performing parathyroidectomy before pregnancy or during the second trimester appears to be a safe and successful strategy, and adherence to this strategy may be most critical for patients with higher calcium levels (≥11.5 mg/dL [2.9 mmol/L]).