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951.
In this paper we present an approach to using historical control data to augment information from a randomized controlled clinical trial, when it is not possible to continue the control regimen to obtain the most reliable and valid assessment of long term treatment effects. Using an adjustment procedure to the historical control data, we investigate a method of estimating the long term survival function for the clinical trial control group and for evaluating the long term treatment effect. The suggested method is simple to interpret, and particularly motivated in clinical trial settings when ethical considerations preclude the long term follow-up of placebo controls. A simulation study reveals that the bias in parameter estimates that arises in the setting of group sequential monitoring will be attenuated when long term historical control information is used in the proposed manner. Data from the first and second National Wilms' Tumor studies are used to illustrate the method.  相似文献   
952.
953.
As both adoptee and psychiatrist, the author brings a double-barreled observation to the issue of search.  相似文献   
954.
Relationships among three motivational variables (negative-personal functions of drinking, alienation, and perceived discrepancies between valued goals and expected success toward valued goals) were evaluated in a group of 257 college drinkers. As predicted, a positive relationship between alienation scores and the extent of discrepancies between values and expectations for academic and social success was found. Negative-personal drinking functions were positively associated with both alienation and value-expectation discrepancies. Results are discussed in terms of heuristic consistency and potential applications.  相似文献   
955.
956.
957.
The design, aims and rationale are outlined of a follow-up study of dropouts from Gamblers Anonymous. A cohort of those attending for the first time and dropping out after more than one meeting was contacted and the cooperators given a structured interview examining factors which may have contributed to decisions to dropout. A comparison group of continuers from the same meeting who had been totally abstinent for at least a year were given the same structured interviews. This first of four parts examines life context factors making it more difficult to maintain attendance, commitment to the treatment program, perceived pre-meeting expectations and reasons for coming, impacts of the first meeting, effects of pressures to maintain attendance and the influence of spouses.  相似文献   
958.
Iron and steel is a key industry in the Indian economy. The author looks at the prospects into the next century and the options facing the industry over the next two decades. New capacity will have to be undertaken but it will undoubtedly be difficult to fund this without external assistance and without diverting resources from other areas. Thus it will be necessary to plan for technological innovation to achieve production objectives, and such technology must be developed in India, or imported and adapted to suit indigenous conditions.  相似文献   
959.
If investors' attitudes toward risk are sufficiently similar to admit an efficient sharing rule that is linear, then this rule also provides sufficient incentives for truthful revelation of private information relevant for joint production decisions.Research support from the Office of Naval Research contract ONR-N00014-79-C-0685 and the National Science Foundation grants SOC-75-21820 and SES-81-08226 is gratefully acknowledged. This paper was prepared during the term of a Guggenheim Fellowship  相似文献   
960.
Ralph R. Sell 《Demography》1983,20(3):299-311
Many theories of geographic mobility assume that the change-of-residence process includes a substantial degree of choice. This paper classifies stated reasons for moving from the 1973 through 1977 Annual Housing Survey into forced, imposed, and preference-dominated categories. About 25 percent of residential mobility and 40 percent of migration occurred under conditions of substantial constraint. Mobility was most often constrained by family dynamics; for migration, occupational relocations frequently imposed the decision-to-move process and determined destinations. The volume of constrained movement indicates that its impact upon individuals, population dynamics, and voluntaristic theories of mobility deserves greater consideration.  相似文献   
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