Table Notes:

  1. Missing data is the result of suppression and/or non-data collection in early years.

  2. Prevalence rate estimates are based on reports to the Alaska Birth Defect Registry. Although p-value estimates are provided to assess the trend (increasing or decreasing) over time, caution should be used in interpretation as data collection methods and data aggregation may vary, leading to systematic differences over time. Reports of defects are only included if diagnosed before the age of three years. For conditions that are commonly diagnosed after the first three years of life, reporting estimates may be systematically lower.

  3. The p-value estimates the probability that the observed slope is different from a slope of zero. By convention an alpha of 0.05 is used to determine significance; p-values are only calculated for defects with 3 or more data points. The p-value estimate is calculated to model the observed rates over time using a generalized linear model with a Poisson distribution and offset of the natural log (ln) of the birth population size under the form:

\[ ln \frac a n = \beta_0 + \beta_1 X_1 + \ln(n) \]

Resources
National Birth Defects Prevention Network
Centers for Diesase Control and Prevention

Contact
Alaska Birth Defects Registry (ABDR)
3601 C Street, Suite 358
Anchorage, AK 99503
(907) 269-3400 phone
(907) 754-3529 fax

Updated: May 19, 2023
Code source: R:\ABDR\Analysis_New\Published Data\trend07_19.Rmd