挤压综合征大鼠血清酶浓度变化的初步研究

目的观察挤压伤大鼠血清肌酸激酶(CK)、肌酸激酶心肌同功酶(CK-MB)浓度的变化,阐明肢体挤压伤大鼠早期是否存在心脏损伤。方法复制挤压伤大鼠动物模型,全自动生化分析仪检测血清CK、CK-MB浓度的变化。结果挤压伤后12h,血清CK、CK-MB浓度显著升高,并持续48h以上。结论肢体挤压伤早期可能有心脏损伤的存在。     

The U.S. study of work incapacity and reintegration

In many countries, including the United States, the number of persons being awarded long-term or permanent disability benefits has risen dramatically in recent years. Government agencies, advocates for the disabled, and others are looking for ways to help persons with disabilities return to the labor force. The Work Incapacity and Reintegration (WIR) Study was developed to address that issue. The United States and five other countries--Germany, Denmark, Sweden, Israel, and the Netherlands--have participated in a cross-national study of work incapacity under the auspices of the International Social Security Association. The study had two objectives: to examine the factors that influence the pattern of work resumption among persons disabled by a back condition and to identify the medical and nonmedical interventions that are most effective in helping such persons reenter the labor force. Samples for the U.S. national study were drawn from four cohorts: Social Security Disability Insurance (DI) beneficiaries, Supplemental Security Income (SSI) beneficiaries, and recipients of temporary disability insurance (TDI) benefits from the states of California and New Jersey. Only the TDI recipients were included in the comparative study. This article discusses the study design and methodology and summarizes the findings of the U.S. national study. Findings from the U.S. study show significant differences between the two cohorts in terms of work resumption and other characteristics. The proportions of respondents from the TDI cohorts who were working at the third and final study contact ranged from 53 percent to 65 percent, compared with less than 5 percent of the DI and SSI respondents. Respondents from the DI and SSI cohorts were on average about 10 years older than the TDI respondents, were less well educated, and reported more physical demands in their usual work. They also reported lower levels of functional capacity, higher levels of pain, and a much greater tendency to have other chronic illnesses. The types of medical treatments provided were remarkably uniform across cohorts and, within cohorts, between those who did and did not resume working. Thus, no medical intervention was identified that showed a significantly higher success rate in terms of facilitating a return to work. However, changes made in the work environment by the employer were an important factor in work reintegration; about 80 percent of respondents who resumed working did so with the help of workplace accommodations. In addition, since respondents with fewer physical demands in their job were more likely to return to work, there appears to be some potential for job retraining as a means of promoting a return to work. The Social Security Administration should consider these findings in developing strategies to help disabled workers reenter the labor force.     

Modeling SSI financial eligibility and simulating the effect of policy options

This article simulates eligibility for Supplemental Security Income (SSI) among the elderly, analyzes factors affecting participation, and looks at the potential effects of various options to modify financial eligibility standards for the federal SSI program. We find that in the estimated noninstitutional elderly population of 30.2 million in the United States in 1991, approximately 2 million individuals aged 65 or older were eligible for SSI (a 6.6 percent rate of eligibility). Our overall estimate of the rate of participation among eligible elderly is approximately 63 percent, suggesting that more than a third of those who are eligible do not participate in the program. The results of our analysis of factors affecting participation among the eligible elderly show that expected SSI benefits and a number of demographic and socioeconomic variables are associated with the probability of participation. We also simulate the effects of various policy options on the poverty rate, poverty gap, annual program cost, the number of participants, and the average estimated benefits among participants. The simulations consider the potential effects of five policy alternatives: Increase the general income exclusion (GIE) from $20 to $80. Increase the earned income exclusion (EIE) from $65 to $260. Increase the federal benefit rate (FBR) by $50 for individuals and $75 for couples and eliminate the GIE. Increase the asset threshold to $3,000 for individuals and $4,500 for couples. Increase the asset threshold to $6,000 for individuals and $9,000 for couples. Using 1991 microdata from the Survey of Income and Program Participation (SIPP) matched to Social Security Administration administrative records and making adjustments reflecting aggregate program statistics, we present the results of our simulations for December 1999. The results show substantial variation in the simulated effects of the five policy alternatives along the various outcome dimensions considered. The simulated effects on the poverty gap of the elderly population range from a 7.9 percent reduction ("Increase the GIE from $20 to $80") to a 0.1 percent reduction ("Increase the EIE from $65 to $260"). All simulated interventions are expected to increase the rate of SSI participation among the elderly from a high of 20.3 percent ("Increase the GIE from $20 to $80") to a low of 0.5 percent ("Increase the EIE from $65 to $260"). We also find that the interventions that have greater estimated effects in terms of increased participation and reduced poverty tend to cost more. At the high end, we estimate that increasing the GIE from $20 to $80 could raise annual federal SSI cash benefit outlays by about 46 percent, compared with only 0.9 percent for increasing the EIE from $65 to $260. Similar to the EIE intervention, raising the resource thresholds by 50 percent would reduce the overall poverty gap of the elderly by only 0.2 percent, would increase SSI participation only modestly (by 1.3 percent), but would entail slightly higher program costs (by 1.4 percent). Increasing the asset threshold by 200 percent would have higher estimated effects on all three outcomes, but it would still be associated with relatively low increases in both costs and benefits. Finally, the simulated effects on the three key outcomes of increasing the FBR by $50 for individuals and $75 for couples, combined with eliminating the GIE, are relatively large but are clearly less substantial than increasing the GIE from $20 to $80. This work relies on data from the SIPP matched to administrative data on federal SSI benefits that provide a more accurate picture of SSI participation than has been feasible for previous studies. We simulate eligibility for federal SSI benefits by applying the program rules to detailed information on the characteristics of individuals and couples based on the rich array of demographic and socioeconomic data in the SIPP, particularly the comprehensive information SIPP provides on assets and monthly income. A probit model is estimated to analyze factors affecting participation among the eligible elderly. Finally, we conduct the policy simulations using altered program rules represented by the policy alternatives and predicted participation probabilities to estimate outcomes under simulated program rules. We compare those simulated outcomes to observed outcomes under current program rules. The results of our simulations are conditional on the characteristics of participants and eligibles in 1991, but they also reflect aggregate adjustments capturing substantial changes in overall participation and program benefit levels between 1991 and 1999.