Type 3 and type 4 errors in the statistical evaluation of clinical trials

On the Move in the community: Protocol for a hybrid 1 trial examining effectiveness and fidelity of a community-based group exercise program for older adults

BACKGROUND

On the Move (OTM), a group exercise program to improve mobility in older adults, is efficacious when delivered by research staff. The next step in the development of OTM as a fully implementable intervention is to conduct an effectiveness study in which the intervention is delivered in community settings by community providers.

METHODS

We describe the methods of a hybrid 1 cluster randomized, single-blind, intervention trial to compare the effectiveness of OTM to a delayed intervention control in 502 community-dwelling older adults across 44 sites. OTM classes are taught by certified instructors in the community twice a week for 12 weeks. Control centers receive no intervention for the first 12 weeks followed by 12-weeks of OTM classes. Participants are assessed at baseline, 12 and 24 weeks. The primary outcome is gait speed. Intervention fidelity, measured by adherence and competence in intervention delivery, is assessed by review of instructor intervention diaries and observation. Organizational, instructor, and participant-level factors which may impact fidelity are assessed using questionnaires, focus groups, and structured interviews.

CONCLUSION

The findings of this trial will 1) establish the effectiveness of OTM on improvements in walking and post-intervention persistence of benefits, 2) assess intervention fidelity and identify the impact of organizational, instructor, and participant level factors on fidelity, and 3) determine the extent to which fidelity moderates the effectiveness of OTM. The information derived from this project will provide valuable insight into the real-world effectiveness of OTM as a health promotion program for improving mobility in older adults.

Comparison between Mid-Infrared (ATR-FTIR) Spectroscopy and Official Analysis Methods for Determination of the Concentrations of Alcohol, SO2, and Total Acids in Wine

The determination of alcohol, SO2, and total acids in wine through conventional laboratory techniques have some limitations related to the amount of the samples, analytical preparation of laboratory staff, and time to carry out the analysis. In recent years, spectroscopic and chromatographic methods have been proposed to determinate simultaneously multiple analytical parameters. The new methods claim the speed of analysis and easy execution. However, they need a validation process that guarantees the reliability of the results to be used in official determinations. This study aimed to evaluate the usefulness of FT-infrared reflectance (FT-IR) to quantify total acid, alcohol, and SO2 concentration in the wines. For this purpose, 156 DOC Italian wines were tested with IR technology, and results were compared to those obtained by official analysis methods. The comparison was performed using two non-parametric statistical methods: the Bland & Altman test and Passing & Bablok regression. Our results showed that the spectrophotometric methods make errors due to interfering contaminants in the sample that can be corrected by blank determination. Therefore, the spectrophotometric methods that use the infrared region of the electromagnetic spectrum can be used by the wine industry and regulators for the wine routine as an alternative to official methodologies.