Changes in the cortisol and oxytocin levels of first-time pregnant women during interaction with an infant: a randomized controlled trial

A Practical Guide to Writing Quantitative and Qualitative Research Questions and Hypotheses in Scholarly Articles

The development of research questions and the subsequent hypotheses are prerequisites to defining the main research purpose and specific objectives of a study. Consequently, these objectives determine the study design and research outcome. The development of research questions is a process based on knowledge of current trends, cutting-edge studies, and technological advances in the research field. Excellent research questions are focused and require a comprehensive literature search and in-depth understanding of the problem being investigated. Initially, research questions may be written as descriptive questions which could be developed into inferential questions. These questions must be specific and concise to provide a clear foundation for developing hypotheses. Hypotheses are more formal predictions about the research outcomes. These specify the possible results that may or may not be expected regarding the relationship between groups. Thus, research questions and hypotheses clarify the main purpose and specific objectives of the study, which in turn dictate the design of the study, its direction, and outcome. Studies developed from good research questions and hypotheses will have trustworthy outcomes with wide-ranging social and health implications.

Cortisol in Peripheral Blood Predicts the Severity and Prognosis in Patients with Liver Failure at 90 Days

Objective

To investigate the cortisol level in peripheral blood in evaluating the severity and prognosis of patients with liver failure.

Methods

A total of 211 inpatients with liver failure were enrolled in Beijing You ‘an Hospital affiliated with Capital Medical University, from September 2018 to January 2020. They were divided into three groups according to the severity of liver failure: early-stage liver failure, medium-stage liver failure and end-stage liver failure. In all patients, peripheral venous blood was gathered to detect the level of peripheral cortisol and related biochemical indexes. Logistic regression was used to screen the risk factors affecting the prognosis of patients at 90 days. A receiver operating curve (ROC) was used to reflect the value of cortisol on the prognosis of patients at 90 days. A model for end-stage liver disease (MELD) was accessed.

Results

Among these 211 patients with liver failure, aged from 19 to 70 years, the average level of cortisol was 351.26 ± 129.78 nmol/L for 101 cases with early-stage liver failure, 281.05 ± 81.31 nmol/L for 58 cases with medium-stage liver failure, and 189.21 ± 89.27 nmol/L for 52 cases with end-stage liver failure (P < 0.05). The level of cortisol in the survival group and the non-survival group was 339.26 ± 121.19 nmol/L and 192.71 ± 67.23 nmol/L, respectively (P < 0.05). The results of logistics regression analysis showed that the odds ratio (OR) and 95% confidence intervals (CI) of cortisol were 1.025 and 1.013–1.038 nmol/L (P < 0.05). MELD results showed that patients with higher MELD scores had lower cortisol content.

Conclusion

The level of cortisol is correlated with the severity of liver failure and decreases with the aggravation of liver failure, suggesting that the level of cortisol could be used as one of the indicators to evaluate the prognosis in patients with liver failure at 90 days.