Using linked data to assess patterns of Early Intervention (EI) referral among very low birth weight infants

Objectives: Access to Early Intervention (EI) services may improve cognitive and behavioral outcomes in very low birth weight infants, but few states have population-based data to evaluate EI outreach efforts. We analyzed Massachusetts (MA) infants born weighing <1,200 g to identify maternal and birth characteristics that predicted EI referral and timing of referral. Methods: MA birth and hospital discharge records (Jan. 1998-Sept. 2000) were linked to EI referral records (Jan. 1998-Sept. 2003) via probabilistic and deterministic methods (88% linkage). Timing of EI referral among infants weighing <1,200 g was examined by infant and maternal characteristics using categorical (0-12 months, 12-36 months, or no referral) time comparisons in the crude analysis. Survival functions calculating median time to referral, and adjusted hazard ratios (HR) with 95% confidence intervals (CI) were calculated for continuous time comparisons of EI referral from birth to 36 months. Results: Of 1,233 infants weighing <1,200 g, 93.2% were referred to EI. After risk adjustment, referral was more likely among multiple-birth infants (HR = 1.17, 95%CI 1.06-1.30) and less likely among infants <28 weeks (HR = 0.70; 95%CI 0.64-0.77) or with low Apgar scores (<5 at 5 min; HR = 0.75; 95%CI 0.62-0.92). EI referrals were lower for infants of black non-Hispanic mothers, and mothers without private insurance (HR = 0.85; 95%CI 0.74-0.98 and HR = 0.77; 95%CI 0.68-0.86, respectively). Conclusions: In MA, most infants born <1,200 g are referred to EI, but disparities exist. Analysis of linked population-based health and developmental services can inform programs in order to reduce disparities and improve access for all high-risk infants.