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Background: The aim was to examine the progression and regression of diabetic retinopathy within a four-year period in a Chinese population with type 2 diabetes mellitus in a community optometry clinic in Hong Kong. Methods: During the period May 2005 to November 2009, 5,160 patients with type 2 diabetes mellitus who had attended at least two diabetic retinopathy screening sessions at a community optometry clinic were included as subjects in this study. All had retinal photographs taken of both eyes, which were of sufficiently good quality for grading. For the purpose of this study, diabetic retinopathy grading was based on the results of the worst eye. The main outcomes were the within four-year incidence of diabetic retinopathy and the incidence of progression and regression of diabetic retinopathy. Results: Of the 5,160 subjects in this study, 3,647 had no diabetic retinopathy, while 1,513 had diabetic retinopathy at the baseline visit. Of those 3,647 subjects with no diabetic retinopathy, the within four-year cumulative incidence of any diabetic retinopathy, mild or moderate non-proliferative diabetic retinopathy and sight-threatening diabetic retinopathy was 15.16 per cent, 14.45 per cent, 0.69 per cent and 0.03 per cent, respectively. Of those 1,513 subjects with diabetic retinopathy at baseline, the within four-year progression incidence of diabetic retinopathy was 6.61 per cent and the regression incidence of diabetic retinopathy was 45.54 per cent. Conclusion: The high regression incidence of diabetic retinopathy suggests that it might not be necessary for all patients with diabetes to be screened annually. Other methods to determine the screening frequency for an individual patient should be explored. [ABSTRACT FROM AUTHOR]

Search query data reflect users' intentions, preferences and interests. The interest in using such data to forecast tourism demand has increased in recent years. The mixed data sampling (MIDAS) method is often used in such forecasting, but is not effective when moving average (MA) dynamics are involved. To investigate the relevance of the MA components in MIDAS models to tourism demand forecasting, an improved MIDAS model that integrates MIDAS and the seasonal autoregressive integrated moving average process is proposed. Its performance is tested by forecasting monthly tourist arrivals in Hong Kong from mainland China with daily composite indices constructed from a large number of search queries using the generalized dynamic factor model. The forecasting results suggest that this new model significantly outperforms the benchmark model. In addition, comparing the forecasts and nowcasts shows that the latter generally outperforms the former. [ABSTRACT FROM AUTHOR]

The dynamic system-of-equations approach has been used to analyze the demand for outbound tourism among a number of destinations. However, this approach has not been applied to the context of the tourist consumption of different products in a given destination. Given the importance of understanding tourists’ consumption behavior to destination management, this study seeks to gain new insights into Hong Kong inbound tourist expenditure patterns using a dynamic system-of-equations approach: the almost ideal demand system model. Based on the estimation of a complete demand system, this study investigates the interactions among the demand for different tourism products (i.e., shopping, hotel accommodation, meals outside hotels, and other) and the impacts of price changes on demand. Tourists from different source markets are examined separately, and the results show that their consumption behavior differs significantly. [ABSTRACT FROM PUBLISHER]