Approximation of the ruin probability using the scaled Laplace transform inversion.

The problem of recovering the ruin probability in the classical risk model based on the scaled Laplace transform inversion is studied. It is shown how to overcome the problem of evaluating the ruin probability at large values of an initial surplus process. Comparisons of proposed approximations with the ones based on the Laplace transform inversions using a fixed Talbot algorithm as well as on the ones using the Trefethen-Weideman-Schmelzer and maximum entropy methods are presented via a simulation study.

Periodic spirometry in occupational setting: improving quality, accuracy, and precision.

OBJECTIVE: Effectiveness of periodic spirometry in medical monitoring depends on spirometry quality. We describe an intervention on spirometry quality and its impact on accuracy and precision of longitudinal measurements. METHODS: The intervention was conducted from 2005 to 2010 in a monitoring program involving approximately 2500 firefighters. Intervention supported adherence to 2005 American Thoracic Society/European Respiratory Society recommendations through monitoring of spirometry quality and longitudinal data precision, technician training, change of spirometer, and quality control. RESULTS: The percentage of forced vital capacity tests meeting the American Thoracic Society/European Respiratory Society criteria increased from 60% to 95% and the mean longitudinal forced expiratory volume in 1 second within-person variation decreased from 6% to 4%. The increased accuracy and precision of measurements and estimated rates of forced expiratory volume in 1 second decline were statistically significant. CONCLUSION: Monitoring of quality and data precision helped to recognize the need for intervention. The intervention improved accuracy and precision of spirometry measurements and their usefulness.

Worksite wellness program for respiratory disease prevention in heavy-construction workers.

OBJECTIVE: To describe a respiratory disease prevention program in a US heavy-construction company. METHODS: The program uses periodic spirometry and questionnaires and is integrated into a worksite wellness program involving individualized intervention. Spirometry Longitudinal Data Analysis (SPIROLA) technology is used to assist the physician with (i) management and evaluation of longitudinal spirometry and questionnaire data; (ii) designing, recoding, and implementing intervention; and (iii) evaluation of impact of the intervention. Preintervention data provide benchmark results. RESULTS: Preintervention results on 1224 workers with 5 or more years of follow-up showed that the mean rate of FEV1 decline was 47 mL/year. Age-stratified prevalence of moderate airflow obstruction was higher than that for the US population. CONCLUSION: Preintervention results indicate the need for respiratory disease prevention in this construction workforce and provide a benchmark for future evaluation of the intervention.

Evaluation of methods to determine excessive decline of forced expiratory volume in one second in workers exposed to diacetyl-containing flavorings.

OBJECTIVE: To evaluate methods for determining excessive short-term decline in forced expiratory volume in one second (FEV1) in diacetyl-exposed workers. METHODS: We evaluated five methods of determining excessive longitudinal FEV1 decline in diacetyl-exposed workers and workers from a comparative cohort: American Thoracic Society (ATS), ACOEM an 8% limit, and a relative and absolute longitudinal limit on the basis of spirometry data variability. Relative risk and incidence of excess decline were evaluated. RESULTS: Incidence of excessive FEV1 decline was 1% in the comparative cohort using ATS and ACOEM criteria, 4.1% using relative limit of longitudinal decline, 4.4% with absolute longitudinal limit of decline, and 5.6% by using the 8% limit. Relative risk of abnormal FEV1 decline in diacetyl-exposed workers was elevated in all evaluated methods. CONCLUSION: Alternative methods for respiratory surveillance in diacetyl-exposed workers may be preferable to ATS or ACOEM.

Spirometry Longitudinal Data Analysis Software (SPIROLA) for Analysis of Spirometry Data in Workplace Prevention or COPD Treatment.

Chronic obstructive pulmonary disease (COPD) is one of the leading causes of morbidity and mortality. Periodic spirometry is often recommended for individuals with potential occupational exposure to respiratory hazards and in medical treatment of respiratory disease, to prevent COPD or improve treatment outcome. To achieve the full potential of spirometry monitoring in preserving lung function, it is important to maintain acceptable precision of the longitudinal measurements, apply interpretive strategies that identify individuals with abnormal test results or excessive loss of lung function in a timely manner, and use the results for intervention on respiratory disease prevention or treatment modification. We describe novel, easy-to-use visual and analytical software, Spirometry Longitudinal Data Analysis software (SPIROLA), designed to assist healthcare providers in the above aspects of spirometry monitoring. Software application in ongoing workplace spirometry-based medical monitoring programs helped to identify increased spirometry data variability due to deteriorating test quality and subsequent improvement following interventions, and helped to enhance identification of individuals with excessive decline in lung function.