CHICAGO — A five-factor scoring system that identifies women who nearly die from obstetric morbidity could potentially offer a more meaningful way to measure maternal health care quality between institutions, according to Dr. Whitney You of Northwestern University's Feinberg School of Medicine in Chicago.
Obstetric mortality has lost most of its value as a measure of maternal health care quality because it is so rare now in the United States, Dr. You said at the annual research meeting of AcademyHealth.
As an objective measure of near-miss obstetric morbidity, the scoring system could hold potential as an outcome measure for hospital case review as well as a reproducible maternal health measure for epidemiologic research aimed at identifying trends and risk factors, she said.
“I'm hoping to use it to figure out who is at greatest risk … where the disparity lies and why,” she said in an interview. Morbidity covers a range from mild fever to near death. “Where is that level where women are very ill, the next step before death?” she asked.
In their study, Dr. You and colleagues used ICD-9 codes to identify 815 women with a high potential for significant obstetric morbidity in a high-volume, urban, tertiary care center over a 2-year period (2001-2002). A maternal-fetal medicine specialist categorized cases according to clinical impression of degree of morbidity: no morbidity (23%), minor morbidity (52%), severe morbidity (19%), and near-miss morbidity (5%), Dr. You explained. The cases then were scored using the five-factor weighted scoring system, in which a score of 8 or more is considered a case of near-miss morbidity. (See table.)
Use of the five-factor scoring system revealed a near-miss obstetric morbidity rate of 4.2% (34 patients). The weighted scoring system showed a 63% sensitivity rate for near-miss morbidity, 99% specificity, positive predictive value of 71% and negative predictive value of 98%, according to results from a poster Dr. You presented at a meeting.
The study is the second to validate the Geller scoring system, developed by Dr. Stacie E. Geller of the University of Illinois at Chicago. “Most of the work has been done with a population at UIC. We wanted to see what would happen with a different population,” Dr. You said.
In Dr. Geller's original work, five clinical factors (organ system failure, ICU admission, transfusion of more than 3 units, extended intubation for more than 12 hours and surgical intervention) were grouped into several scoring system alternatives. A scoring system based on all five factors showed the highest specificity (93%), but even a four-factor system, which eliminated organ system failure, achieved a specificity of 78% (J. Clin. Epidemiol. 2004;57:716-20).
Additional studies can help determine whether other factors could be added to identify cases of near-miss morbidity missed in this investigation, Dr. You noted.
In this study, a single maternal-fetal medicine provider reviewed all the cases. Since then, an obstetric anesthesiologist and another experienced maternal-fetal medicine specialist have reviewed the cases as well. Dr. You and her associates plan to calculate sensitivity and specificity based on these additional reviews. “After we get that information, we can decide if it can be a good tool to use in other settings,” she said.
Adapting the scoring system to other types of institutions presents a key challenge.
“We need to figure out how it works in a rural setting or community hospital,” she said. These smaller facilities often refer severely ill patients to tertiary care institutions, “so they may never get a patient that needs multiple transfusions or intubation for an extended time. Our hope is to level the grading system, just because it's so hard to compare one hospital to another.”
Dr. You conducted this study while she was a National Research Service Award postdoctoral fellow at the Institute for Healthcare Studies under an award from the Agency for Healthcare Research and Quality.
ELSEVIER GLOBAL MEDICAL NEWS