Dimensionality and summary measures of the SF-36 v1.6: comparison of scale- and item-based approach across ECRHS II adults population.

OBJECTIVES: The objective of this study was twofold: 1) to confirm the hypothetical eight scales and two-component summaries of the questionnaire Short Form 36 Health Survey (SF-36), and 2) to evaluate the performance of two alternative measures to the original physical component summary (PCS) and mental component summary (MCS). METHODS: We performed principal component analysis (PCA) based on 35 items, after optimal scaling via multiple correspondence analysis (MCA), and subsequently on eight scales, after standard summative scoring. Item-based summary measures were planned. Data from the European Community Respiratory Health Survey II follow-up of 8854 subjects from 25 centers were analyzed to cross-validate the original and the novel PCS and MCS. RESULTS: Overall, the scale- and item-based comparison indicated that the SF-36 scales and summaries meet the supposed dimensionality. However, vitality, social functioning, and general health items did not fit data optimally. The novel measures, derived a posteriori by unit-rule from an oblique (correlated) MCA/PCA solution, are simple item sums or weighted scale sums where the weights are the raw scale ranges. These item-based scores yielded consistent scale-summary results for outliers profiles, with an expected known-group differences validity. CONCLUSIONS: We were able to confirm the hypothesized dimensionality of eight scales and two summaries of the SF-36. The alternative scoring reaches at least the same required standards of the original scoring. In addition, it can reduce the item-scale inconsistencies without loss of predictive validity.

Impact of insemination technique, semen quality and oocyte cryopreservation on pronuclear morphology of zygotes derived from sibling oocytes.

Pronuclear morphology seems to be an important predictive value of zygote development and integrity. In this study we want to evaluate the effect of insemination technique, male factor and oocyte cryopreservation on pronuclear morphology of zygotes derived from sibling oocytes in our Centre of Reproductive Medicine, Department of Obstetrics and Gynecology, Arcispedale S. Maria Nuova, Reggio Emilia, Italy. Subjects (n = 190) were submitted to IVF cycles with non-frozen and frozen sibling oocytes. Morphological evaluations were assessed using zygote pronuclear morphology (pronuclei, nucleoli and axis) in four groups: Group 1: 144 zygotes from 85 conventional IVF cycles with non-frozen oocytes; Group 2: 164 zygotes from 85 intracytoplasmic sperm injection (ICSI) cycles with Group 1 patients' sibling frozen oocytes; Group 3: 221 zygotes from 123 ICSI cycles with non-frozen oocytes; Group 4: 197 zygotes from 123 ICSI cycles with Group 3 patients' sibling frozen oocytes. No differences between Group 1 and Group 2 were seen. Group 3 was statistically different from Group 4 in relation to the nucleolar morphology. Oocyte cryopreservation procedure modified the nucleolar morphology of zygotes only in the presence of poor semen quality.

Performance comparison of Likert and binary formats of SF-36 version 1.6 across ECRHS II adults populations.

OBJECTIVES: To evaluate a binary response structure of SF-36 items assessing scaling assumptions, reliability, and validity of questionnaire. METHODS: An optimal scaling accounting for the nonmetric properties of the data was used to reduce SF-36 Likert item responses to give a binary coding. The binary recoding was compared with the original format regarding item analysis, underlying latent components and know-groups clinical validity using ordered correlation/regression methods. Data from the European Community Respiratory Health Survey Follow-up (ECRHS II) of 8854 subjects from 25 centers were analyzed to cross-validate the binary coding proposal. RESULTS: Overall, the testing comparison produces results indicating that the binary recoding of the SF-36 scales meets at least similar standards without jeopardizing the underling structure of the original format. Internal binary consistency shows comparable values with the Likert ones and these are always higher than the minimum suggested. The Principal Component structure was well replicated and know-groups validity gives similar research findings for symptomatic, long-term illness and depression differences. CONCLUSIONS: Although there is lost of information due to the reduction of response's chance, our results indicate that the SF-36 binary recoding gives the possibility to suggest a new version of smarter and easier methodology of administration, compilation, score calculation, and data processing. Consequently, it may be an alternative to the existing shorter versions, suitable in administering in clinical setting and clinical trials, in subjects with serious diseases, and by telephone.