Before-after Evaluation Research Articles

Comparison of empirical Bayes and full Bayes approaches for before–after road safety evaluations

The empirical Bayes (EB) approach has now gained wide acceptance among researchers as the much preferred one for the before-after evaluation of road safety treatments. In this approach, the before period crash experience at treated sites is used in conjunction with a crash prediction model for untreated reference sites to estimate the expected number of crashes that would have occurred without treatment. This estimate is compared to the count of crashes observed after treatment to evaluate the effect of the treatment. This procedure accounts for regression-to-the-mean effects that result from the natural tendency to select for treatment those sites with high observed crash frequencies. Of late, a fully Bayesian (FB) approach has been suggested as a useful, though complex alternative to the empirical Bayes approach in that it is believed to require less data for untreated reference sites, it better accounts for uncertainty in data used, and it provides more detailed causal inferences and more flexibility in selecting crash count distributions. This paper adds to the literature on comparing the two Bayesian approaches through empirical applications. The main application is an evaluation of the conversion of road segments from a four-lane to a three-lane cross-section with two-way left-turn lanes (also known as road diets). For completeness, the paper also summarizes the results of an earlier application pertaining to the evaluation of conversion of rural intersections from unsignalized to signalized control. For both applications, the estimated safety effects from the two approaches are comparable.

Effect of a clinical decision support system on adherence to a lower tidal volume mechanical ventilation strategy

Purpose The purpose of the study was to measure the effect of a computerized decision support system (CDSS) on adherence to tidal volume ( V T) recommendations. Materials and Methods We performed a prospective before-after evaluation study on applied V T to examine the impact of a CDSS on adherence to our local protocol in a 30-bed mixed medical-surgical intensive care unit of a university hospital. All intensive care unit patients who were intubated and mechanically ventilated for at least 1 hour were included. Results A total of 3 663 674 V T records of 696 patients were analyzed. The average volume greater than 6 mL/kg predicted body weight (PBW) and the mean percentage of ventilation time with V T greater than 6 mL/kg PBW decreased after intervention by 6.0% and 3.4%, respectively (not significant). A stronger effect of the decision support intervention was found among patients with longer duration of mechanical ventilation (>24 hours): for these patients, the average V T in exceeding 6 mL/kg PBW and the mean percentage of ventilation time with V T greater than 6 mL/kg PBW decreased after intervention by 18.3% ( P = .01) and 9.5% ( P = .01), respectively. In this group, the mean percentage of ventilation time with V T records between 8 and 10, between 10 and 12, and greater than 12 mL/kg PBW decreased by 21.8% ( P = .006), 21.5% ( P = .047), and 24.7% ( P = .155), respectively. Conclusions The use of a CDSS, integrated in a patient data management system, improves implementation of a lower V T mechanical ventilation strategy for patients ventilated for longer than 24 hours.

Facilitating access to voluntary and community services for patients with psychosocial problems: a before-after evaluation

Facilitating access to voluntary and community services for patients with psychosocial problems: a before-after evaluation

Facilitating access to voluntary and community services for patients with psychosocial problems: a before-after evaluation

BackgroundPatients with psychosocial problems may benefit from a variety of community, educational, recreational and voluntary sector resources, but GPs often under-refer to these through lack of knowledge and time. This study evaluated the acceptability and effectiveness of graduate primary care mental health workers (GPCMHWs) facilitating access to voluntary and community sector services for patients with psychosocial problems.MethodsPatients with psychosocial problems from 13 general practices in London were referred to a GPCMHW Community Link scheme providing information and support to access voluntary and community resources. Patient satisfaction, mental health and social outcomes, and use of primary care resources, were evaluated.Results108 patients consented to take part in the study. At three-month follow-up, 63 (58%) had made contact with a community service identified as suitable for their needs. Most were satisfied with the help provided by the GPCMHW in identifying and supporting access to a suitable service. There was a reduction in the number of patients with a probable mental health problem on the GHQ-12 from 83% to 52% (difference 31% (95% CI, 17% – 44%). Social adjustment improved and frequencies of primary care consultations and of prescription of psychotropic medications were reduced.ConclusionGraduates with limited training in mental health and no prior knowledge of local community resources can help patients with psychosocial problems access voluntary and community services, and patients value such a scheme. There was some evidence of effectiveness in reducing psychosocial and mental health problems.

Evaluation of a decision aid for making choices about intubation and mechanical ventilation in chronic obstructive pulmonary disease

To assist patients with chronic obstructive pulmonary disease (COPD) in advance planning for life-threatening exacerbations, we developed a structured decision aid that describes the process, risks, and outcomes of intubation and mechanical ventilation (MV). Thirty-three patients with severe COPD took part in a before-after evaluation study. At baseline, only two participants (6%) reported that they had already made an advance decision about MV. After reviewing the decision aid, 31 participants (94%) reported that they had made a choice, which in 23 cases (74% of those deciding) was to forego MV. These choices were associated with more accurate expectations of MV outcome, and reduced decisional conflict. Qualitatively, participants who would accept MV emphasized their wish to prolong life, whereas those who would forego MV were more influenced by the burdens of treatment and the perception of a poor long-term outcome. However, there was evidence that 24% of participants did not completely comprehend the decision aid and 27% found the experience to be stressful. These findings indicate that a decision aid for MV helps patients plan for life-threatening exacerbations, and may be a useful adjunct to counseling for some patients with severe COPD.

Couples, Existential Psychotherapy, and Myocardial Infarction: A Ten Year Evaluation Study

Existential psychotherapy with couples after the occurrence of a myocardial infarction can be a useful, effective, and productive service approach in combination with medical services and cardiac rehabilitation services. In this article the existential treatment dynamics of holding, telling, mastering, and honoring with couples after a heart attack are described and illustrated. In addition, data from a 10-year before-after field evaluation study is reported, which supports the usefulness of the treatment approach.

A comparative evaluation of a fibromyalgia rehabilitation program.

To compare an evidence-based clinical fibromyalgia program, referred to as Fibro-Fit, with results of controlled clinical trials. An interdisciplinary group education and exercise program with 36 sessions over 12 weeks was used. Demographic, clinical, and outcome variables were collected on 149 participants, of whom 71% completed the program. Outcomes included measures of self-efficacy, pain, physical fitness, function, and coping skills. Results of the prospective before-after evaluation showed statistically significant (P < 0.005) improvements in all outcomes except for grip strength. These results were comparable with controlled clinical trials found in the literature. Data suggest that smoking, fibromyalgia support groups, and medications may be important modifiable factors. Results suggest that Fibro-Fit was effective in improving physical impairments and function. Further investigation is required to refine the effective components of these programs and determine how modifiable factors can be used to improve outcomes.

The Program for Rheumatic Independent Self-Management: A Pilot Evaluation

The 'Program for Rheumatic Independent Self-Management' (PRISM) is an interdisciplinary programme that integrates group education and individualised treatment using the principles of self-management, adult learning, case management and self-efficacy enhancement. This study is a before-after evaluation of 57 individuals who attended PRISM. Outcome measures were selected to measure self-efficacy, disability, pain and ability to cope. The mean self-efficacy score increased immediately following the programme and this improvement was maintained at 6-month follow-up. Disability decreased from baseline to 6-month follow-up. There was a decrease in the mean level of pain from post-class to 6-month follow-up. All of these changes were statistically significant. These preliminary findings suggest that PRISM may be effective in enhancing self-efficacy, and reducing disability and pain.