Utilization of nuclear medicine scintigraphy in Taiwan, 1997–2009

Long-term prognostic value of computed tomography-based attenuation correction on thallium-201 myocardial perfusion imaging: A cohort study

BACKGROUND

Myocardial perfusion imaging (MPI) is a well-established diagnostic tool to evaluate coronary artery disease (CAD) and also an effective prognostic tool for patients with CAD. However, few studies investigated the prognostic value of attenuation correction (AC) in MPI, and the results were controversial.

OBJECTIVES

To investigate the prognostic value of computed tomography (CT)-based AC thallium-201 (Tl-201) MPI.

METHODS

A total of 108 consecutive patients who underwent Tl-201 MPI and received coronary angiography within 90 days were included. Medical records were reviewed and missing information was completed after telephone contact. The prognostic value was evaluated by Kaplan-Meier analysis, univariable and multivariable Cox proportional hazards model.

RESULTS

After a mean follow-up of 7.72 ± 3.72 years, 27 patients had died, 41 had been readmitted for cardiovascular (CV)-related events and 44 had reached the composite of death plus CV-related re-admission. Kaplan-Meier curves for all-cause mortality for SSS with a cutoff value of 13 for AC and 16 for non-AC (NAC) images showed a significant difference between the two curves for both AC and NAC images (p = 0.011 for AC and p = 0.021 for NAC). In the multivariable model, SSS and SRS showed similar independent predictive values in predicting all-cause mortality and composite of all-cause mortality plus CV-related re-admission, in both AC and NAC images. Subgroup analysis implicated that AC MPI possibly provided better risk stratification in obese patients.

CONCLUSION

CT-based AC and NAC MPI showed similar value and were the only significant predictors for the composite of mortality and CV events.

Trends in the utilization of nuclear medicine and radiopharmaceuticals in an aging population

AIM

To investigate the trends in the utilization of nuclear medicine procedures and radiopharmaceuticals in an aging population and to establish the prediction models.

METHODS

Based on Taiwan's National Health Insurance Research Database, a longitudinal study was conducted from 2000 to 2012. Descriptive statistics were adopted to analyze the frequencies and distributions of nuclear medicine procedures. Multiple linear regression analysis was applied to establish the prediction model for the utilization of nuclear medicine.

RESULTS

The utilization of myocardial perfusion imaging increased most significantly, i.e. 250 per million population (pmp) increment annually, followed by the whole-body bone scan (176 pmp) and whole-body PET scan (100 pmp) in Taiwan during the period of 2000-2012. The use rate of nuclear medicine procedure which the first quartile (Q1) of age at examination above 35 years fits the regression model: Use rate expected year = 0.03 Q1 of age at examination × use rate baseline year + 14797 life expectancy expected year / life expectancy baseline year - 15030. Adversely, the use rate of procedure which Q1 of age at examination below 35 years fits the model: Use rate expected year = 0.01 Q1 of age at examination × use rate baseline year - 4565 life expectancy expected year / life expectancy baseline year + 4749. In addition, the similar models were found in the applications of radiopharmaceuticals.

CONCLUSION

This study demonstrates the age at examination and life expectancy can be used to predict the utilities of nuclear medicine procedures and radiopharmaceuticals in an aging population. Nuclear medicine practice applied in the geriatrics would increase significantly with the aging of population.

Myocardial perfusion scintigraphy in Taiwan from 2005 to 2009

OBJECTIVE

To analyze the utilization of myocardial perfusion scintigraphy (MPS) in Taiwan within the universal healthcare system, the National Health Insurance (NHI) from 2005 to 2009, and to compare with European surveys.

METHODS

On the basis of Taiwan's National Health Insurance Research Database of 2005-2009, a retrospective population-based analysis was conducted. Descriptive statistics were provided on the frequencies of and distributions in the utilization of MPS during the period. In addition, correlation analysis was applied to identify correlated factors in the utility of MPS.

RESULTS

The annual number of MPS procedures performed was estimated to be 76 448 on average in 2005-2009 and 3361 per million population (pmp) over the period. The frequency increased by 45%, from 3008 pmp in 2005 to 4371 pmp in 2009, with an annual increase rate of 11.9%. The expenditure on MPS increased by 51%, from 12.3 million USD in 2005 to 18.55 million USD in 2009, with an annual increase rate of 12.9%. The average cost of identifying a coronary artery disease (CAD) case with MPS was 248 USD, with a 2.6% annual increase rate. Most patients were more than 50 years old when they received the MPS examination, whereas inpatients were much older. In addition, most of the MPS practices were performed in medical centers and regional hospitals, although an apparent increase was seen in district hospitals on outpatients. As a consequence, the rate of CAD diagnoses by MPS decreased over time.

CONCLUSION

The numbers, frequencies, and expenses of MPS practices have increased in Taiwan during the period 2005-2009, especially for outpatients. The application rate of MPS in Taiwan was higher than that in Europe, likely because of the high accessibility to MPS procedures within the NHI system. This experience in Taiwan may serve as a reference for illustrating the trends in the use of MPS procedures in countries with a universal healthcare system.