Table 2.

Results of the studies which reported the effects of oseltamivir treatment initiated for influenza

Study	Influenza type	Study group	Oseltamivir treatment	Results and/or interpretations
Hien TT. et al. (33)	Pandemic H1N1	292 hospitalized patients Mean age 26.4 years (1–69 years)	All patients received standard oseltamivir treatment	Treatment days/patient RT-PCR On the 3rd day, 3.62% negative On the 5th day, 5.86% negative After 24 hours, 228/292 patients were afebrile Mild disease in all patients
Yu H et al. (36)	Pandemic H1N1	1291 patients Mean age 20 years (12–26 years) No need for intensive care	983 (76%) patients were treated with oseltamivir on the third day (mean) of the symptoms	Decrease in development of radiographically confirmed pneumonia with treatment, shorter lasting fever and decreased viral RNA scattering, no mortality
Ko JH. et al. (38)	Pandemic H1N1	804 patients Mean age 5 years (0–18 years) 95 intensive care patients	98.8% patients were treated with antiviral medication. Oseltamivir was given to 776 (98.6%) of 787 patients. Use of antiviral medication in the first two days of disease onset: 73%	No mortality was found possibly in relation with early diagnosis and early initiation of antiviral drugs
Jain S. et al. (40)	Pandemic H1N1	Data of 268 patients related with use of antiviral medication are present Mean age 21 years (21 days-86 years) 122 patients <18 years 67 intensive care patients	200 patients received antiviral treatment. 188 patients received oseltamivir treatment. The time of initiation of antiviral treatment was the third day (mean)	Use of antiviral drugs was found to be beneficial especially when initiated in the early period. When the patients who were admitted to intensive care or who died were examined, the rate of use of antiviral drugs in the first 48 hours following onset od symptoms was observed to be lower. 19 patients (7%) mortality: 90% received antiviral treatment. The mean time between disease onset and initiation of antiviral treatment : 8 days None of the patients received antiviral treatment in the first 48 hours following onset of symptoms
Coffin SE. et al. (43)	Seasonal influenza	1 257 pediatric intensive care patients Mean age 1.7 years	264 children were given oseltamivir in the first 24 hours after hospital admission	Initiation of oseltamivir in the first 24 hours after hospitaliation was found to be related with shorter hospital stay. However, no difference was found in terms of duration of stay in pediatric intensive care unit, hospital mortality rate and representation rate.
Louie JK. et al. (44)	Pandemic H1N1	1 950 intensive care patients 1859 hospitalized patients (95%) Data related with antiviral treatment are present Mean age 37 years (1 week-93 years) Survival in 1260 patients	1 676 (90%) patients were treated with neurominidase inhibitors. 183 patients (10%) did not receive treatment. 1 671 patients (99.76%) received oseltamivir.	A correlation was found between use of neurominidase inhibitors in treatment and survival: 107 (58%) of 183 patients who were untreated, 75% of 1676 patients who were treated (p≤.0001). As early as treatment is initiated, as higher the survival rate (p<.0001). Treatment initiated in 5 days following onset of symptoms increased the survivial rate compared to the patients who were given no treatment (p<.05). The mortality rate was 26% in all hospitsalized patients who received antiviral treatment and 42% in the ones who did not receive treatment.
Morgan CI. et al. (45)	Seasonal influenza: Influenza A 67.6% Influenza B 30.2% H1N1 season: 94.3% confirmed H1N1, 4.8% untyped	312 patients hospitalized in relation with H1N1 Seasonal influenza in 222 children who needed intensive care Mean age for H1N1 influenza 107 months (56–154 months) Mean age for seasonal influenza 68 months (15–128 months)	For H1N1: oseltamivir treatment in the first 48 hours following presentation: 96% For seasonal influenza: oseltamivir treatment in the first 48 hours following presentation: 15%	Significantly lower morbidity and mortality in critically ill children who were found to have H1N1. This was related with the fact that children who had H1N1 were treated with oseltamivir with a higher rate compared to the ones who had seasonal influenza. Mortality rate for seasonal influenza: 11% Mortality rate for H1N1: 0%
Farias JA et al. (46)	Pandemic H1N1	437 patients with acute respiratory tract infection in pediatric intensive care unit 147 (34%) critically ill patients İnfluenza A H1N1 Mean age 10 months	28-day survival following pediatric intensive care unit admission: 92% with oseltamivir treatment 86% with oseltamivir treatment in 24 hours 28-day mortality following pediatric intensive care unit admission: 91% with oseltamivir treatment 68% with oseltamivir treatment in the first 24 hours	Use of oseltamivir in the first 24 hours following presentation at hospital has prophylactic effect OR 0.2 (CI 95% 0.07–0.54) 28-day mortality rate: 39% (n:57)