Socio-demographic characteristics of the study population
The control group included 27 males and 23 females aged 20-65 years old, (43.25±12.65) years on average. There were 22 cases of ASA grade II and 28 cases of grade III. The observation group consisted of 29 males and 21 females aged 20-64 years old, (42.91±12.73) years on average. There were 23 cases of ASA grade II and 27 cases of grade III. The two groups had similar gender ratio, age and ASA grade (P>0.05). The socio-demographic characteristics are listed in Socio-demographic characteristics of study populationIndependent t testchi-square test