Background:
The prevalence of autism spectrum disorders (ASD) has been increasing, with a recent CDC estimate of 1 of 68 children. As this cohort ages, millions of individuals will advance into adulthood with this diagnosis. A recent report from Kaiser Permanente Northern California (KPNC), an integrated medical care program serving about 3.5 million members, showed that adults with ASD have a higher prevalence of hypertension (HTN), than a comparable group not known to have ASD (non-ASD). We are unaware of data regarding HTN control in persons with ASD.
Hypothesis:
HTN control rates will be lower in ASD than in non-ASD KPNC members because of communication difficulties associated with ASD.
Methods:
We identified 1,507 KPNC members, age >18 years, with ASD (ICD-9-CM codes 299.0, 299.8. 299.9) during the time period, 1/1/2008-12/31/2012, of which 218 had HTN (2 outpatient diagnoses of HTN, or 1 outpatient diagnosis of HTN with a prescription for anti-hypertensive medication within 12 months of HTN identification). For each ASD patient, we identified 5 comparison KPNC non-ASD members with HTN, matched for age, sex, race, and year of HTN identification (n=1,090). We determined all primary care outpatient blood pressures (BP) recorded within 12 months after HTN identification and used the final BP obtained for analysis. We excluded 14 members with no BPs (1 ASD, 13 controls) and 39 members, age >65 years (8 ASD, 31 controls). HTN control was defined as systolic BP <140 and diastolic BP <90 mm Hg. BP control rates were age-adjusted using weighting derived from the 2000 U.S. census.
Results:
The mean age was 43.6 years for ASD and 43.9 for controls (p=0.74). The HTN control rate was higher for ASD (84.2%; age-adjusted 84.9%) than for controls (73.5%, age-adjusted 71.7%) (p=0.001). Members with ASD had more BP measurements (mean 6.0, standard deviation [s.d.] 6.2) than controls (mean 4.8, s.d. 4.4) (p=0.0008).
Conclusion:
HTN was better controlled in adults with ASD than in non-ASD adults, possibly related to more frequent measurement of BP.