A nurse-delivered, clinic-based intervention to address intimate partner violence among low-income women in Mexico City: findings from a cluster randomized controlled trial.

BACKGROUND: Rigorous evaluations of health sector interventions addressing intimate partner violence (IPV) in low- and middle-income countries are lacking. We aimed to assess whether an enhanced nurse-delivered intervention would reduce IPV and improve levels of safety planning behaviors, use of community resources, reproductive coercion, and mental quality of life. METHODS: We randomized 42 public health clinics in Mexico City to treatment or control arms. In treatment clinics, women received the nurse-delivered session (IPV screening, supportive referrals, health/safety risk assessments) at baseline (T1), and a booster counselling session after 3 months (T2). In control clinics, women received screening and a referral card from nurses. Surveys were conducted at T1, T2, and T3 (15 months from baseline). Our main outcome was past-year physical and sexual IPV. Intent-to-treat analyses were conducted via three-level random intercepts models to evaluate the interaction term for treatment status by time. RESULTS: Between April and October 2013, 950 women (480 in control clinics, 470 in treatment clinics) with recent IPV experiences enrolled in the study. While reductions in IPV were observed for both women enrolled in treatment (OR, 0.40; 95% CI, 0.28-0.55; P < 0.01) and control (OR, 0.51; 95% CI, 0.36-0.72; P < 0.01) clinics at T3 (July to December 2014), no significant treatment effects were observed (OR, 0.78; 95% CI, 0.49-1.24; P = 0.30). At T2 (July to December 2013), women in treatment clinics reported significant improvements, compared to women in control clinics, in mental quality of life (ß, 1.45; 95% CI, 0.14-2.75; P = 0.03) and safety planning behaviors (ß, 0.41; 95% CI, 0.02-0.79; P = 0.04). CONCLUSION: While reductions in IPV levels were seen among women in both treatment and control clinics, the enhanced nurse intervention was no more effective in reducing IPV. The enhanced nursing intervention may offer short-term improvements in addressing safety planning and mental quality of life. Nurses can play a supportive role in assisting women with IPV experiences. TRIAL REGISTRATION: Clinicaltrials.gov ( NCT01661504 ). Registration Date: August 2, 2012.

Real-time three-dimensional transesophageal echocardiography: improvements in intraoperative mitral valve imaging.

BACKGROUND: Successful surgical repair of a regurgitant mitral valve (MV) is dependent on a comprehensive assessment of its complex anatomy. Although there is limited evidence of the feasibility and accuracy of intraoperative real-time 3-dimensional transesophageal echocardiography (RT3DTEE) in MV surgery, its use is increasing worldwide. We designed this prospective observational study of patients with mitral regurgitation to test initial findings on the accuracy of RT3DTEE images in the diagnosis of MV prolapse and chordal rupture relative to 2D imaging and to assess the potential of RT3DTEE for visualizing leaflet clefts. METHODS: TEE-certified anesthesiologists examined 62 consecutive patients undergoing MV surgery by acquiring a full standard set of 2D TEE sections and 3D zoom recordings. Offline, 2D and 3D images were presented independently and in randomized order to 2 expert interpreters. Accuracy was determined using the surgical findings as the "gold standard." RESULTS: Surgical inspection identified 52 cases of MV prolapse (MVP). RT3DTEE correlated stronger with the surgical findings than 2D TEE for detection and localization of MVP (difference in proportions=33.9%, P<0.001) and chordal rupture (difference in proportions=25.8%, P<0.001). The superiority of RT3DTEE was significant for scallops A2, P1, P2 in MVP and A2, P2 in chordal rupture (all P<0.05). In 22 patients, leaflet clefts were also surgically repaired, and RT3DTEE was feasible in accessing them (κ=0.65, confidence interval [0.44, 0.81]). CONCLUSION: Although 2D TEE is currently the standard tool for intraoperative imaging in MV surgery, RT3DTEE improves the visualization of MV pathology and increases the accuracy of interpretation by facilitating spatial orientation. Further investigations, particularly those aimed at establishing its cost effectiveness, are indicated.

The impact of data transformations on concentration-response modeling.

Concentration-response studies are performed to investigate the potency of the substance under investigation. Data are typically evaluated using non-linear regression. A common model is the log-logistic model which includes parameters for lower and upper boundary of mean response, EC50 and Hill slope. Often, response and/or concentration data are transformed before proceeding with the analysis of their relationship. This is motivated by practical reasons, including comparability of results across different assays. We prove mathematically that a linear transformation of data will not change the EC50 and Hill slope estimates and only results in an identical transformation of the estimated parameters for lower and upper boundary of mean response. However, fixing some of the parameters may lead to erroneous estimates. This is of practical relevance when data are corrected for background signal and normalized by background corrected solvent control and a reduced model is used in which the response range is fixed between 100% and 0%. Computer simulations and a real data example are used to illustrate the impact of data transformations on parameter estimation. We further shed light on some common problems arising in the analysis of concentration-response data. Recommendations for practical implementation in concentration-response analysis are provided.