Methods
The current study was conducted on all PCR-positive H1N1 patients
hospitalized at Imam Khomeini Hospital, Tehran, Iran, from 21 March to
21 September 2019. The sample size was calculated as 64. After obtaining
all due permission, records of PCR-positive patients with H1N1 influenza
were retrieved and searched.
For this cross-sectional study, inclusion criteria were H1N1 influenza
cases confirmed by the PCR test between 21 March and 21 September 2019.
Exclusion criteria were incomplete or missing clinical information and
laboratory and imaging records. All information, including demographic
data, clinical presentations, prescribed medicines, and imaging and
laboratory records, were retrieved and recorded in a questionnaire.
Demographic data, age and gender, and the history of other coexisting
diseases were retrieved and recorded. Influenza risk factors were
defined according to the Mendel textbook of Infectious diseases. The
information regarding commonly used immunosuppressive medications and
drugs used in the emergency department and infectious diseases wards
were also extracted from credible reference books.
All patient records of the clinical presentations (cough, sputum,
dyspnea, orthopnea, hemoptysis, fever, and chills) were extracted from
the files and recorded. Vital signs, including oxygen saturation,
systolic and diastolic blood pressure, pulse rate, respiratory rate, and
temperature, were also retrieved and recorded.
The information regarding laboratory test results, including WBC, Hb,
plat, ESR, CRP, ALP, ALT, and AST, were also recorded in the data
sheets. The CT scan imaging records of the patients were also extracted
and compiled. This information included the number of involved lung
lobes, axial location, anteroposterior location, shape, and pattern of
the lesion, margin, and other lesion characteristics. Disease outcomes
regarding survival or death were also extracted and included. The
imaging procedure was carried out using a Siemens Emotion 6 Slice CT
Scanner at Imam Khomeini Hospital’s facility.
The data gathering instrument was a questionnaire designed according to
the data needed for the study. This questionnaire contained demographic
data, clinical presentations, laboratory findings, CT scan reports, and
the outcomes of the diseases.
The research ethics board of the hospital approved the study. The need
for a priori informed consent was waived due to the noninterventional
study design. Private information of the patients was kept confidential
by the researchers, and it was set that if the data needed to be
reproduced, this should be done with the permission of the hospital
ethics committee.
Data were analyzed using the SPSS software version 22. In the
descriptive analysis, quantitative variables were reported with median
and interquartile range and qualitative variables with number and
percentage. The analytical part assessed the relationship between the
disease outcomes and vital signs and laboratory findings with the
Mann-Whitney U test. The Chi-Square test was used to examine the
relationship between disease outcome and clinical symptoms, risk
factors, and imaging findings. In the multivariable logistic regression,
using the Enter method, the outcome of the disease was determined
according to the influential and significant parameters, and the results
were reported as odds ratios (OR) with a 95% confidence interval.