| dc.description.abstract | Background: In Norway, dental care services are mostly paid for privately by the individuals themselves. Periodontitis is a gum disease requiring ongoing treatment creating a potential economic burden for the patient. Periodontitis is irreversible, but preventable, and the prevalence is unknown. The disease is the primary cause of tooth loss in the adult population. Regarding screening for periodontitis, there are disagreements on the appropriate starting age and economic evaluations appear to be lacking. Objective: To assess the cost-effectiveness of screening for periodontitis compared with today’s practice in 60 year old individuals, over a lifetime horizon. Methods: A state transition Markov model was developed to assess changes in costs and quality-adjusted tooth years (QATYs) by a hypothetical screening intervention for periodontitis. There is limited available literature on the progression of periodontal disease, and no available data on the utility associated with the disease. Sub-analyses of 40 and 80 years olds were compared to the main analysis to reflect heterogeneity. Sensitivity analyses were performed to explore and reduce uncertainty, and a value of information (VOI) analysis was conducted to investigate to what extent acquiring additional information would be of value. Results: Over a lifetime horizon, the incremental cost-effectiveness ratio of the screening intervention was NOK 5 101 per QATY gain, for screening offered from the age of 60. Sensitivity analyses explored uncertainty in several parameters. If the willingness to pay (WTP) threshold was above NOK 40 000, the screening intervention was more likely to be cost-effective than today’s practice. The VOI analysis emphasized the need for additional research. The value of acquiring perfect information per individual per year should not exceed NOK 1 050 per QATY gain. Conclusion: The decision of cost-effectiveness is uncertain, as there is no predetermined WTP threshold for the new intervention. Screening was considered cost-effective for 60 year olds for WTP thresholds above NOK 5 101 per QATY. The results indicated reduced costs by introducing screening from the age of 40 compared with today’s practice. The conclusion of this thesis highlights the need for new research in order to reduce the uncertainties of the results. | eng |