How feasible is it to abandon statistical significance? A reflection based on a short survey.

BACKGROUND: There is a growing trend in using the "statistically significant" term in the scientific literature. However, harsh criticism of this concept motivated the recommendation to withdraw its use of scientific publications. We aimed to validate the support and the feasibility of adherence to this recommendation, among researchers having declared in favor of removing the statistical significance. METHODS: We surveyed signatories of an article published that defended this recommendation, to validate their opinion and ask them about how likely they will retire the concept of statistical significance. RESULTS: We obtained 151 responses which confirmed the support for the mentioned publication in aspects such as the adequate interpretation of the p-value, the degree of agreement, and the motivations to sign it. However, there was a wide distribution of answers about how likely are they to use the concept of "statistical significance" in future publications. About 42% declared being neutral, or that would likely use it again. We described arguments referred by several signatories and discussed aspects to be considered in the interpretation of research results. CONCLUSIONS: The responses obtained from a proportion of signatories validated their declared position against the use of statistical significance. However, even in this group, the full application of this recommendation does not seem feasible. The arguments related to the inappropriate use of statistical tests should promote more education among researchers and users of scientific evidence.

Effects of low-power LED and therapeutic ultrasound in the tissue healing and inflammation in a tendinitis experimental model in rats.

This work evaluated the anti-inflammatory response of low-power light-emitting diode (LED) and ultrasound (US) therapies and the quality and rapidness of tendon repair in an experimental model of tendinitis, employing histomorphometry and Raman spectroscopy. Tendinitis was induced by collagenase into the right tendon of 35 male Wistar rats with an average weight of 230 g. The animals were randomly separated into seven groups of five animals each: tendinitis without treatment-control (TD7 and TD14, where 1 and 2 indicated sacrifice on the 7th and 14th day, respectively), tendinitis submitted to US therapy (US7 and US14) and tendinitis submitted to LED therapy (LED7 and LED14). Contralateral tendons of the TD group at the 14th day were used as the healthy group (H). US treatment was applied in pulsed mode at 10 %, 1 MHz frequency, 0.5 W/cm(2), 120 s. LED therapy parameters were 4 J/cm(2), 120 s, daily dose at the same time and same point. Sacrifice was performed on the 7th or 14th day. Histomorphometric analysis showed lower number of fibroblasts on the 14th day of therapy for the US-treated group, compared to the TD and LED, indicating lower tissue inflammation. Raman showed that the LED group had an increase in the amount of collagen I and III from the 7th to the 14th day, which would indicate more organized fibers and a better quality of the healing, and US showed lower collagen I synthesis in the 14th day compared to H, indicating a lower tissue reorganization.

Hepatitis B: knowledge, vaccine situation and seroconversion of dentistry students of a public university.

BACKGROUND: Viral hepatitis B (VHB) is an occupational risk for dentists. It is necessary that dental students start clinical practice immunized with the vaccine, response monitored and informed about the means of transmission of the disease. Rarely, there are studies, which evaluate concomitantly knowledge of these academics and their vaccine situation. OBJECTIVES: To evaluate the knowledge about Hepatitis B, the vaccine situation and the immunization status of dental students and to investigate the probable correlation between the status of immunization, vaccination membership and adherence to the test of seroconversion and associated factors. PATIENTS AND METHODS: 189 students from the dentistry course at the Federal University of Piaui (UFPI) who attended from the 3rd to 9th period were invited to participate in the research. Their knowledge about HBV, attitude regarding protection and their vaccine situation were assessed through a self-administered form. Antibodies against surface antigens of Hepatitis B virus (Anti-HBs) and against the antigens of the virus nucleous of Hepatitis B (Anti-HBc total) were measured qualitatively using the enzyme-linked immunosorbent assay (ELISA). RESULTS: Of the 179 students surveyed, 58.1% knew about the degree of virulence of the Hepatitis B virus (HBV). As to the means of transmission, 98.3% considered blood transmission, 82.6% plates and cutlery, 15.6% cough and 12.3% vertical transmission. Most students (87.4%) knew that they should take 3 doses of the vaccine and 62.2% completed the immunization schedule. A minority of students (48.6%) knew the about the Anti-HBs test and 5.6% took the test. Among the students who reported having taken three doses of the vaccine, 12.5% were not seroconverted. There was no significant correlation between the variables. CONCLUSIONS: Dental academics were unsure about the means of infection and prevention against HBV. Many of them had not completed the immunization scheme and did not have the test of seroconversion. The serological analysis revealed unprotection, even after students completed the vaccination schedule.