PURPOSE: To define the epidemiology of severe ocular trauma in Singapore. METHODS: A population-based incidence study involving all Singapore citizens and residents. Two government-administered databases were used to ...
详细信息
PURPOSE: To define the epidemiology of severe ocular trauma in Singapore. METHODS: A population-based incidence study involving all Singapore citizens and residents. Two government-administered databases were used to capture information on severe ocular trauma in Singapore. The national hospital discharge database provided information on incident episodes of hospitalized ocular injury, defined as any ocular injury requiring hospitalization. The national medical savings database provided information on incident episodes of open globe injury, defined as any open globe injury requiring acute ophthalmic surgery. The 1990 Singapore Census was used as denominator data. RESULTS: From 1991 to 1996, the overall annual incidence rate of hospitalized ocular injury was 12.6 per 100,000, and the annual incidence rate of open globe injury was 3.7 per 100,000. Nearly 15% of open globe injury was associated with an intraocular foreign body. Although a 20% decline in the rate of hospitalization over this 6-year period was observed, no distinct time trend in the rate of open globe injury was seen. Men had fourfold higher rates of injury than women. A. bimodal age pattern of ocular injury was observed, with a peak in injury rates in young adults and another in people over 70 years, Racial variation in rates of injury was seen in men but not in women (with Indian men having twice the risks than either Chinese or Malay men). CONCLUSIONS: Severe ocular trauma in Singapore varied with age (highest in young adults and elderly), gender, and race (highest in Indian men), suggesting demographic-specific differences in exposure to high-risk injury settings. (Am J Ophthalmol 1999;128: 345-351, (C) 1999 by Elsevier Science Inc. All rights reserved.)
Surveys have been, and will most likely continue to be, the source of data for many empirical articles. Likewise, the difficulty of making valid statistical inferences in the face of missing data will continue to plag...
详细信息
Surveys have been, and will most likely continue to be, the source of data for many empirical articles. Likewise, the difficulty of making valid statistical inferences in the face of missing data will continue to plague researchers. In an ideal situation, all potential survey participants would respond;in reality, the goal of an 80 to 90% response rate is very difficult to achieve. When nonresponse is systematic, the combination of low response rate and systematic differences can severely bias inferences that are made by the researcher to the population. It is important for the researcher to assess the potential causes of nonresponse and the differences between the observed values in the sample compared to what may have been gained if the sample was complete, particularly when the response rate is low. There are methods available that substitute imputed values for missing data, but these methods are useless if the researcher lacks knowledge of how the responders and nonresponders may differ. With regard to statistical inference, the researcher also should be aware of the difference between a convenient sample and a probability sample. Valid statistical inference assumes that the probability of characteristics observed in the sample bear some relationship to their occurrence in the population. For example, in a simple random sample each member of the accessible population has an equal chance of inclusion in the sample. A convenient sample lacks the statistical properties of a probability sample that allow the validity of its inferences to be assessed strictly from a mathematical framework. The context of the research and the type of data being gathered greatly affect the validity of any generalizations the researcher makes with regard to the population the convenient sample attempts to represent.
暂无评论