title: [Use of the control group selected by a method of matched samples in the evaluation of the health status of children from complicated pregnancies].
abstract: A method of matched samples consisting in selection of "a partner" for each examined individual according to the established criteria of similarities is one of the methods used owing to its apparent organizational ease in selecting of the control group. The control group selected in this way was used in the evaluation of the effect of bleeding during the first 16 weeks of pregnancy on the health status and physical development of children. The paper points out the advantages of using the control group selected by the method of matched samples. It also presents the difficulties encountered in practice. Typical of this study technical methods and statistical tests used in evaluation of the results were juxtaposed and discussed, then compared to those used when a group was randomly selected. Special attention was paid to 3 basic problems: Time stability is selection of criteria for matched samples. Adjustment of age differences within pairs. Two methods were used for comparison of the anthropometric measurements. The first one consisted in levelling of the differences by the method of regression, the second in the use of various available growth curves. The results obtained by both methods were compared by means of statistical tests. The third problem concerned adequacy of the tests used when the control group was selected by the method of matched samples. Results obtained by application of t-Student test for paired samples were compared to those obtained by t-Student test for independent variables. The merits of the method of matched samples were presented using some examples (table I, II, III). Eleven conclusions were drawn from evaluation of suitability of selecting the control group according to the method of paired samples. These can be put into three main groups: Showing in what kind of studies the control group selected by the method of matched samples is payable . Showing various inconveniences caused by selection of the control group by the method of matched samples, Conclusions concerning methodological or other benefits drawn from this method. It is clearly indicated in this paper that the control group selected by the method of matched samples is recommended only in certain investigations. Before the final decision is taken all pros and cons should be considered.
mesh_terms: D000886:Anthropometry / Q000379:methods; D002648:Child; D002675:Child, Preschool; D005069:Evaluation Studies as Topic; D005260:Female; D005500:Follow-Up Studies; D006128:Growth; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D011247:Pregnancy; D011249:Pregnancy Complications, Cardiovascular / Q000503:physiopathology*; D011446:Prospective Studies; D011597:Psychomotor Performance / Q000502:physiology*; D012044:Regression Analysis; D012107:Research Design; D014592:Uterine Hemorrhage / Q000503:physiopathology*
vernacular_title: Zastosowanie grupy kontrolnej metoda doboru par w ocenie stanu zdrowia dzieci z powikłanej ciazy.