title: [Clinical comparison of four types of IUDs made in China].
abstract: In order to compare the clinical efficacy of 4 types China made IUDs, this paper reported the study of a total of 1227 cases who, from January 1973 to June 1975, had used 1 of the 4 types of IUDs -- the stainless steel ring, metallic plastic mixed ring, metallic and silastic copper-shaped devices.  The study was not a random allocation but was done, 1 type by 1, during the period.  Life table method and logrank test were used to calculate and analyze the different events among these 4 types.  1147 cases were followed up for more than 5 years.  The 5-year followup rate was 93.48%.  Patients using these 4 types were comparable among themselves since the distribution of their age, gravida, para, and time of insertion were the same or quite similar.  Study results were as follows:  the cumulative pregnancy rates of the 2 copper V-shaped IUDs were significantly lower than that of the steel and mixed ring (p0.01); the cumulative expulsion rate of the steel ring was comparatively high, but there was no statistical difference compared with the others; bleeding was the main cause of medical removals; there was a higher cumulative medical removal rate of the V-shaped than that of the ring-shaped and also a significant difference between them (p0.01).  However, at every year, the year-cumulative continuation rates were similar despite the difference of the events of discontinuation rates.  The fact that 51.72-62.29% of the subjects continued to wear these IUDs indicated that the efficacy of the 4 types of IUDs was satisfactory even after a 5-year course.
authors.forename: H M
authors.initials: HM
authors.lastname: Fan
authors.forename: X M
authors.initials: XM
authors.lastname: Huang
authors.forename: M H
authors.initials: MH
authors.lastname: Wu
mesh_terms: D001723:Birth Rate; D003267:Contraception; D003268:Contraception Behavior; D003274:Contraceptive Devices, Female; D003710:Demography; D003933:Diagnosis; D004467:Economics; D005069:Evaluation Studies as Topic; D005193:Family Planning Services; D005298:Fertility; D007434:Intrauterine Devices; D011153:Population; D011157:Population Dynamics; D018873:Pregnancy Rate; D012106:Research; D012107:Research Design; D013672:Technology
keywords: Comparative Studies; Contraception; Contraception Continuation; Contraception Failure; Contraception Termination; Contraceptive Methods; Contraceptive Usage; Demographic Factors; Economic Factors; Evaluation; Examinations And Diagnoses; Family Planning; Fertility; Fertility Measurements; Iud; Measurement; Population; Population Dynamics; Pregnancy Rate; Research And Development; Research Methodology; Studies; Technology; Vaginal Rings