Validity and responsiveness of EQ-5D-5L and SF-6D in patients with health complaints attributed to their amalgam fillings: a prospective cohort study of patients undergoing amalgam removal

Background Evidence of health utility changes in patients who suffer from longstanding health complaints attributed to dental amalgam fillings are limited. The change in health utility outcomes enables calculating quality-adjusted life-year (QALY) and facilitates the comparison with other health conditions. The purpose of this study was to estimate the validity and responsiveness of the EQ-5D-5L and SF-6D utilities following removal of dental amalgam fillings in patients with health complaints attributed to their amalgam fillings, and examine the ability of these instruments to detect minimally important changes over time. Methods Patients with medically unexplained physical symptoms, which they attributed to dental amalgam restorations, were recruited to a prospective cohort study in Norway. Two health state utility instruments, EQ-5D-5L and SF-6D, as well as self-reported general health complaints (GHC-index) and visual analogue scale (EQ-VAS) were administered to all patients (n = 32) at baseline and at follow-up. The last two were used as criteria measures. Concurrent and predictive validities were examined using correlation coefficients. Responsiveness was assessed by the effect size (ES), standardized response mean (SRM), and relative efficiency. Minimally important change (MIC) was examined by distribution and anchor-based approaches. Results Concurrent validity of the EQ-5D-5L was similar to that of SF-6D utility. EQ-5D-5L was more responsive than SF-6D: the ES were 0.73 and 0.58 for EQ-5D-5L and SF-6D, respectively; SRM were 0.76 and 0.67, respectively. EQ-5D-5L was more efficient than SF-6D in detecting changes, but both were less efficient compared to criteria-based measures. The estimated MIC of EQ-5D-5L value set was 0.108 and 0.118 based on distribution and anchor-based approaches, respectively. The corresponding values for SF-6D were 0.048 and 0.064, respectively. Conclusions In patients with health complaints attributed to dental amalgam undergoing amalgam removal, both EQ-5D-5L and SF-6D showed reasonable concurrent and predictive validity and acceptable responsiveness. The EQ-5D-5L utility appears to be more responsive compared to SF-6D. Trial registration The research was registered at ClinicalTrials.gov., NCT01682278. Registered 10 September 2012, https://clinicaltrials.gov/ct2/show/NCT01682278.

Health Complaints Attributed to Dental Amalgam: A Retrospective Survey Exploring Perceived Health Changes Related to Amalgam Removal

Background: Many patients have complex health complaints they attribute to dental amalgam. There is some evidence of symptom relief after removal of amalgam. Objective: The aims of this study were to assess the total symptom load in patients with all their amalgam fillings removed, and to investigate the self-reported improvement of health with regard to precautions taken under amalgam removal and time since removal. Methods: The survey was distributed to all members (n=999) of the Norwegian Dental patients association in 2011. The study participants returned the questionnaires anonymously by means of a pre-stamped envelope. The questionnaire asked for sociodemographic data, subjectively perceived health status, complaints persisting after amalgam removal and self-reported changes in symptoms after amalgam removal. Results: A total of 324 participants were included in the study. The majority of the participants reported improved health after amalgam removal, even though the mean degree of severity of complaints was still high. Exhaustion and musculoskeletal complaints were most severe, and reflects the fact that 38% of the participants reported poor to very poor current health. With regard to amalgam removal, associations between improved health, number of precautions applied, and time since removal were found. Conclusion: Most of the participants in this study reported improvement of health after amalgam removal even though they still suffered a high complaint load. Since absolute symptom load is a robust predictor for general health outcome and socioeconomic burden for society, a possible intervention, which enables patients to further improve their health status is desirable.

Evaluation of Mercury Contamination in Patients and Water during Amalgam Removal

ABSTRACT Aim The aim of this study was to evaluate mercury levels in wastewater and in patients during the removal of dental amalgam restorations. Materials and methods To test for mercury levels, patients were tested before and after amalgam restoration removal. To test for mercury emissions, samples of constant volume of wastewater from high-speed drills were collected before and during amalgam restoration removal. Results Although the systemic mercury levels were lower than the limit of biological tolerance, all patients had increased levels after dental restorations. All samples of wastewater had increased mercury levels too. Conclusion The urinary levels of mercury increased with dental amalgam removal using a high-speed drill. During the process of amalgam removal, water used for cooling the dental drill was contaminated with mercury. Clinical significance The mercury released by the physical action of the drill, the replacement material and especially the final destination of the amalgam waste can increase contamination levels that can be a risk for human and environment health. How to cite this article Oliveira MT, Constantino HV, Molina GO, Milioli E, Ghizoni JS, Pereira JR. Evaluation of Mercury Contamination in Patients and Water during Amalgam Removal. J Contemp Dent Pract 2014;15(2):165-168.