Table 4. Logistic regression analysis for intellectual and developmental status and other relevant variables predicting birth outcomes, U.S., (n=3,345,474).
| Variables | Preterm birth | Low birth weight | Stillbirth | |||
|---|---|---|---|---|---|---|
| aOR | 95% CI | aOR | 95% CI | aOR | 95% CI | |
| Disability status | ||||||
| Women without IDD (referent) | 1 | 1 | 1 | 1 | 1 | 1 |
| Women with IDD | 1.46*** | 1.26 - 1.69 | 1.61*** | 1.27 - 2.05 | 2.40*** | 1.70 - 3.40 |
| Race and Ethnicity | ||||||
| Non-Hispanic White (referent) | 1 | 1 | 1 | 1 | 1 | 1 |
| Non-Hispanic Black | 1.32*** | 1.31 - 1.34 | 1.25*** | 1.22 - 1.28 | 1.94*** | 1.88 - 2.01 |
| Hispanic | 0.91*** | 0.90 - 0.92 | 0.65*** | 0.64 - 0.67 | 1.02 | 0.98 - 1.06 |
| Non-Hispanic Other | 0.96*** | 0.95 - 0.98 | 1.09*** | 1.07 - 1.12 | 1.07** | 1.02 - 1.12 |
| Age group | ||||||
| <24 (referent) | 1 | 1 | 1 | 1 | 1 | 1 |
| 25-34 | 0.96*** | 0.95 - 0.97 | 0.74*** | 0.73 - 0.76 | 1.01 | 0.98 - 1.05 |
| >34 | 1.16*** | 1.14 - 1.17 | 0.81*** | 0.79 - 0.83 | 1.49*** | 1.43 - 1.55 |
| Type of insurance coverage | ||||||
| Private insurance (referent) | 1 | 1 | 1 | 1 | 1 | 1 |
| Medicare | 0.80*** | 0.76 - 0.83 | 0.77*** | 0.71 - 0.83 | 0.73*** | 0.64 - 0.82 |
| Medicaid | 0.72*** | 0.69 - 0.75 | 0.71*** | 0.66 - 0.77 | 0.66*** | 0.58 - 0.75 |
| Uninsured | 0.84*** | 0.80 - 0.88 | 0.68*** | 0.62 - 0.74 | 1.02 | 0.89 - 1.17 |
| Comorbidity † | ||||||
| No comorbidity | 1 | 1 | 1 | 1 | 1 | 1 |
| 1 or more comorbidities | 1.59*** | 1.58 - 1.61 | 1.41*** | 1.39 - 1.43 | 1.40*** | 1.36 - 1.44 |
| Median household income for patient's ZIP code | ||||||
| 4th quartile:$63,000 + (referent) | 1 | 1 | 1 | 1 | 1 | 1 |
| 1st quartile:$1-$38,999 | 1.17*** | 1.15 - 1.18 | 1.00 | 0.98 - 1.02 | 1.32*** | 1.27 - 1.38 |
| 2nd quartile:$39,000-$47,999 | 1.08*** | 1.07 - 1.09 | 1.03* | 1.00 - 1.05 | 1.20*** | 1.15 - 1.25 |
| 3rd quartile:$48,000-$62,999 | 1.03*** | 1.02 - 1.05 | 1.00 | 0.98 - 1.02 | 1.15*** | 1.10 - 1.20 |
| Hospital location | ||||||
| Rural (referent) | 1 | 1 | 1 | 1 | 1 | 1 |
| Urban | 1.26*** | 1.24 - 1.28 | 1.11*** | 1.08 - 1.14 | 0.91*** | 0.86 - 0.95 |
| Teaching status of hospital | ||||||
| Non-teaching referent) | 1 | 1 | 1 | 1 | 1 | 1 |
| Teaching | 1.38*** | 1.37 - 1.40 | 1.19*** | 1.17 - 1.21 | 1.17*** | 1.14 - 1.21 |
| Ownership of hospital | ||||||
| Private, investor-owned (referent) | 1 | 1 | 1 | 1 | 1 | 1 |
| Public, government, non-federal | 1.01 | 0.99 - 1.02 | 0.97* | 0.94 - 1.00 | 1.04 | 0.99 - 1.10 |
| Private, not-for-profit | 0.93*** | 0.92 - 0.95 | 1.00 | 0.97 - 1.02 | 0.96 | 0.93 - 1.00 |
| Region of hospital | ||||||
| Northeast (referent) | 1 | 1 | 1 | 1 | 1 | 1 |
| Midwest | 1.01 | 0.99 - 1.02 | 1.00 | 0.97 - 1.02 | 1.09*** | 1.04 - 1.15 |
| South | 1.13*** | 1.11 - 1.14 | 1.09*** | 1.07 - 1.11 | 1.17*** | 1.12 - 1.22 |
| West | 1.18*** | 1.16 - 1.19 | 0.99 | 0.96 - 1.01 | 1.11*** | 1.07 - 1.17 |
| Year | ||||||
| Calendar Year = 2007 (referent) | 1 | 1 | 1 | 1 | 1 | 1 |
| Calendar Year = 2008 | 1.00 | 0.99 - 1.02 | 1.09*** | 1.07 - 1.12 | 1.03 | 0.98 - 1.07 |
| Calendar Year = 2009 | 0.95*** | 0.94 - 0.96 | 1.08*** | 1.06 - 1.11 | 0.96 | 0.92 - 1.00 |
| Calendar Year = 2010 | 0.98*** | 0.96 - 0.99 | 1.31*** | 1.28 - 1.35 | 1.02 | 0.98 - 1.06 |
| Calendar Year = 2011 | 0.87*** | 0.86 - 0.89 | 1.31*** | 1.28 - 1.35 | 0.98 | 0.94 - 1.02 |
*
p<0.05;
**
p<0.01;
***
p<0.001.
Acronyms: IDD- Intellectual and developmental disability, aOR-Adjusted odd ratios, AHRQ- Agency for Health Care Research and Quality; CI-confidence interval.
†
Comorbidity variable is generated using the AHRQ comorbidity software.15,25 Patients are considered to have comorbidity if their discharge records show that they have one more of the 29 types of patient comorbidities identified by AHRQ using the standard method by Elixhauser.15
Data source: Nationwide Inpatient Sample, Healthcare Cost and Utilization Project, 2007-2011