Transition of Stroke Incidence and Evaluation of Recombinant Tissue Plasminogen Activator in Thailand

Abstract

Background: Stroke is one of the major public health problems in Thailand. Its incidence is expected to increase due to the country's ageing population and increasing trend of risk factors. Thailand hopes to achieve the non-communicable disease (NCD) global targets recommended by the World Health Organization. The impact of demographic and epidemiologic change on the incidence of stroke between 2010 and 2040 and the benefit of achieving NCD global targets in the general population, should be quantified. In 2008, the National Health Security Office included recombinant tissue plasminogen activator (rtPA) in the benefits package of the Universal Coverage Scheme. The benefit of rtPA is to reduce or prevent brain infarction and minimize the long-term disability and neurologic impairment. However, the thrombolytic agent can also cause symptomatic intracerebral hemorrhage, which increases the odds of death. In addition, increasing the number of new stroke cases leads to consequent strains on health resource. Whereas the cost-effective of thrombolytic therapy has been examined, there has been less focus on the overall budgetary. Therefore, the cost of rtPA treatment and its effect on mortality at the national level is need to be evaluated. Objectives: This study aims to 1) project the incidence of stroke among the Thai population between 2010 and 2040. 2) quantify the impact of demographic transition and trend of risk factors on the incidence of stroke 3) estimate the benefit of achieving the NCD targets on reducing the incidence of stroke 4) investigate the trend of thrombolysis among ischemic stroke patients, estimate the cost of treatment with rtPA among ischemic stroke patients and determine the effect of rtPA treatment on 30-day fatality among ischemic stroke Methods: The macro simulation based on Markov model was applied to project the incidence of stroke between 2010 and 2040. The base case scenario, which holds the level of risk factors at the initial year constant, was used to quantify the impact of demographic change on the incidence of stroke. A trend of risk factor scenario was then simulated by combining trends in stroke risk factors to estimate the additional effect. Finally, targeted NCD scenario including three NCD targets, a 25% reduction in hypertension, a 10% reduction in insufficient physical activity and a 30% reduction in smoking, were incorporated to determine their impact on the projected incidence of stroke. To estimate cost of rtPA and examine its effect of on mortality, we used three national datasets comprising hospital costs from the Division of Health Insurance, Ministry of Public Health, the inpatient database of the Universal Health Coverage scheme from the National Health Security Office and the civil registration database from the Ministry of Interior. The association between rtPA and 30-day case fatality was determined using multiple logistic regression. Results: Based on demographic change alone, Thailand would face an approximately 44% or 60% increase in stroke incidence within 30 years. If the current trend of stroke risk factors persists, an extra 1.4% or 7.7% are estimated. Among modifiable risk factors, hypertension has the most contribution to new stroke events. Achieving three NCD global target (reducing 25% of hypertension, 30% of smoking and 10% of insufficient physical activity) could be averted new stroke event from the demographic effect by approximately 5.5%. The rate of thrombolytic treatment has increased from 1.6% in 2011 to 3.8% in 2014. Cost of treatment in itPA usage was 4 times higher than without rtPA. Patients treated with rtPA had an increasing 30-day case fatality rate of 11% (OR 1.11, 95% CI 1.03 - 1.21) compared to those without rtPA after adjustment for other variables. Conclusion: Population ageing is expected to be the major contribute to the rise in stroke incidence in Thailand over the next decade. A substantial increase in stroke is projected due to a doubling in the number of elderly people in the next 30 years. Trends in risk factors will also accelerate future stroke incidence in the Thai population. A steady declining trend of smoking could not counterbalance the rise of stroke incidence added by the adverse trend of diabetes and overweight. Achieved NCD target would not be enough to offset the increase of stroke incidence from the influence of demographic factors. It is recommended that public health policy to lower diabetes and overweight through improved diet and physical activity, implementation of WHO best buy interventions in particular taxation on tobacco, alcohol, sugar-sweetened beverages; control of marketing advertisement and sponsorship by industry; and control of availability of alcohol, and promoted mass media in physical activity, should be the high policy priorites. In addition, supporting program for early detection and effective coverage of hypertension and diabetes are necessary. The rate of using rtPA in the Universal Health Coverage Scheme has been increasing during the present study period but remains low. More detailed data collection is needed in the future to evaluate the benefit and harm of rtPA use in Thailand. Keywords: stroke incidence, projection, thrombolysis rate, Recombinant Tissue Plasminogen Activator, ischemic stroke, cost of treatment