Site Rate Research Articles

P-641 - The importance of rigor in post-baseline assessments in cns clinical trials

Inappropriate subjects may be enrolled in a study when enrollment pressures cause inflated baseline severity scores. An increasing number of studies now include methods such as blinded independent centralized ratings (CR) to ensure that appropriate subjects are entered into the trial. Post-baseline factors such as functional unblinding, expectation bias and rater drift can also affect outcomes. Independent raters, blind to study visit, can minimize functional unblinding and expectation bias. Continuous calibration of CR can minimize rater drift. To examine studies with both site ratings (SR) and CR to determine how critical post-baseline blinding and continuous calibration are. A trial of acute schizophrenia used CR for the PANSS and SR for the BPRS on the same subjects. A Parkinson's psychosis study used CR in the US and SR ex-US to assess subjects using the SAPS. A GAD trial used CR of subjects enrolled by SRs’ SIGH-A evaluations. In the schizophrenia trial, CR separated the active comparator and one of two test arms. SR separated the active comparator but neither test arm. In the Parkinson's psychosis study, pimavanserin showed greater separation with CR than SR. In the GAD trial, CR had lower placebo response than SR, independent of subject selection. Data from several studies support the continued importance of rater blinding and independence, post subject selection. Results suggest that precision of ratings beyond baseline can increase the sensitivity of findings in a clinical trial, decrease placebo response rates and potentially eliminate Type II errors.

Adoption of Hospital Policies for Prevention of Perinatal Group B Streptococcal Disease—United States, 1997

Group B streptococcal (GBS) infections are the leading bacterial cause of disease and deaths among newborns in the United States. In 1993, the annual cost of caring for newborns with sepsis caused by group B Streptococcus was an estimated $294 million. A survey of hospital GBS disease prevention practices in 1994 indicated that those hospitals with a prenatal screening policy had fewer neonatal GBS disease cases. In 1996, to promote a coordinated approach to prevention, CDC issued consensus guidelines about GBS disease prevention that were endorsed by the American College of Obstetricians and Gynecologists and the American Academy of Pediatrics. These consensus guidelines recommend using either a screening-based strategy or a risk-based strategy for identifying women who should receive intrapartum antimicrobial prophylaxis. To evaluate adoption of the consensus guidelines, in 1997, hospitals in eight surveillance areas were surveyed, and the results were compared with findings of a similar survey conducted in 1994. The proportion of hospitals with prevention policies in each site was compared with the site's rate of early-onset disease to assess the impact of the prevention policies. This report presents the survey findings, which indicate that more hospitals have adopted GBS disease prevention policies since issuance of the consensus guidelines.