Indicator                          Definition

Preterm birth (%)             Percentage of all live births

                                     less than 37 completed weeks gestation

Late preterm birth (%)      Percentage of all live births

                                     between 34 and 36 weeks gestation

Uninsured women (%)      Percentage of women ages 15-44

                                      with no source of health insurance coverage

Women smoking (%)       Percentage of women ages 18-44

                                      who currently smoke either every day or some
                                      days and have smoked at least 100 cigarettes in their lifetime

Where possible, national data sources were used so that data would be consistent for each state and jurisdiction-specific premature birth report card. Therefore, data provided on the report card may differ from data obtained directly from state or local health departments and vital statistics agencies. Thiscould be due to multiple causes. For example, as part of the Vital Statistics Cooperative Program, states are required to send NCHS natality and mortality data for a given year by a specific date. Sometimes states receive data after this date, which may result in slight differences in the rates calculated using NCHS-processed data and state-processed data. Another reason preterm birth rates, in particular, may vary could be due to differences in the way NCHS and the states calculate variables and impute missing data. Collaboration among March of Dimes chapters, state and local health departments and other local partners, will provide a deeper understanding of specific contributors to preterm birth.

Grading Methodology
Preterm birth report card grades were based solely on preterm birth rates and not rates of uninsured women, women smoking or late preterm birth. Grades for the 50 states, District of Columbia, Puerto Rico and United States total were calculated with respect to the U.S. Department of Health and Human Service’s Healthy People (HP) 2010 objective for preterm birth of “no more than 7.6% of live births.” To determine the progress needed to achieve the HP 2010 objective, a “HP 2010 score” was calculated using the following formula: (preterm birth rate – HP 2010 objective) / standard deviation of 2005 state and D.C. preterm birth rates. Scores were rounded to one decimal place. Each jurisdiction was then assigned a grade based on the following criteria:

For example: Vermont’s HP 2010 score = (9.0% - 7.6%) / 1.87 = 0.7 Based on this score, VT received a “B” grade in 2008

A = Preterm birth rate less than or equal to 7.6% (HP score less than or equal to 0)

B = Preterm birth rate greater than 7.6%, but less than 9.5% (HP 2010 score greater than 0, but less than 1)

C = Preterm birth rate greater than or equal to 9.5%, but less than 11.3% (HP 2010 score greater than or equal to 1, but less than 2)

D = Preterm birth rate greater than or equal to 11.3%, but less than 13.2% (HP 2010 score greater than or equal to 2, but less than 3)

F = Preterm birth rate greater than or equal to 13.2% (HP 2010 score greater than or equal to 3)

Preterm Birth Rate Ranking
The report card includes a ranking of preterm birth rates for the 50 states, District of Columbia and Puerto Rico (52 jurisdictions), with a 1 denoting the “best” (or lowest) preterm birth rate and a rank of 52 denoting the “worst” (or highest) preterm birth rate. Ranks were calculated based on more than one decimal place, thus, there are no ties.

Selected Contributing Factors
The March of Dimes has identified and provided geographically-specific data for three “selected contributing factors”: uninsured women, women smoking and late preterm births. While these important and potentially modifiable factors represent prevention opportunities for consumers, health professionals, policymakers and employers, they do not represent an exhaustive list of contributors to preterm birth. With the momentum provided by the premature birth report card, states and jurisdictions may likely identify and take action to address other potentially modifiable contributors that play an important role in the prevention of preterm birth.