The information of this study comes from a population database of a Peruvian survey study that englobes health personnel (e.g. physicians, nurses, psychologists, etc.), medical students and general population, which is not related which the other two groups. The information from this database englobes the after-lockdown period due to COVID-19 in Peru
3.1 Study design and selection criteria
Information of recruited participants between the ages of 18 and 80 years old was used. The participants were recruited between 20th July and 18th August 2020. From this online survey database, the information of 400 participants was obtained. A complete description is shown in table 1.
Participants younger than 18 years old, with insufficient knowledge of Spanish language and with medical difficulties to participate in the online survey were not included in this study. Additionally, the information of health personnel and medical students were also excluded from the analysis.
Each participant was fully informed of this study and gave their consent to participate. This study was approved by the ethics committee from the Faculty of Medicine of the Peruvian University Cayetano Heredia and carried out in accordance with the Helsinki Declaration and the ethical standards of the APA.
3.2 Data collection
3.2.1 Online Survey
For the data recollection, an online survey was carried out. Due to the restrictive policies for avoiding COVID-19 infection, all instruments and questions were digitalized and programmed in a survey internet free program (Google Forms). The recollected questions included: (1) the informed consent and the declaration of not being under 18 years old, (2) questions regarding age, gender, district, confession/faith and occupation, (3) previous medical diagnosis and medication intake, (4) assessment of the COVID-19 peri-traumatic distress index (CPDI) for COVID-19 pandemic, (5) GAD-7 and PHQ-9 instruments.
Finally, it was also asked to the participant through these online electronic questionnaires different questions related to COVID-19 infection. These questions were the following: “in the last 14 days, did you have cough, difficulty to breath, sore throat and fever?” (COVID_1), “do you have positive results for any sort of COVID-19 test?” (COVID_2), “have you been hospitalized (or are you hospitalized at the moment) due to COVID-19?” (COVID_3), “do you have relatives with positive results for any sort of COVID-19 test?” (COVID_4), “do you have relatives who have been hospitalized due to COVID-19?” (COVID_5) and “do you have relatives who have passed away due to COVID-19?” (COVID_6).
After the participant filled the information of the online survey, the data was saved in a Microsoft Excel 2019 file for further analysis.
3.2.2 COVID-19 Peritraumatic distress index (CPDI)
The COVID-19 peritraumatic distress index (CPDI) was first applied in China (18) and lately validated in other countries (i.e. Brazil, Iran and Peru) (19,20). This instrument was designed for a population to evaluate changes related to mood, behavior, cognitive skills, circadian rhythm and other somatic symptoms due to the COVID-19 pandemic.
This instrument consists in 24 items, with a four-factor design: negative mood, cognition, behavioral change, somatization and hyper-arousal/exhaustion. Each item was evaluated by using Likert elements (from 0 to 4: never, occasionally, sometimes, often and most of the time). The sum of each value per question results in the raw score. The display score is obtained by adding 4 to the raw score and used to calculate the CPDI severity degrees. For this reason, this instrument defines different categories for peritraumatic stress due to COVID-19 pandemic: normal (0 to 28 display points), mild (29 to 52 display points) and severe (53 to 100 display points).
3.2.3 Depressive and anxiety symptoms
The Peruvian version of the PHQ-9 (21) was used to assess the severity of depressive symptoms. The PHQ-9 delivers values in the range between 0 and 27. The highest value indicates a higher depressiveness. This instrument was validated in Peru with a representative sample (n = 30446), showed good internal consistency (Cronbach's α = 0.87). This inventory defines different categories for depressiveness: minimal (1 to 4 points), mild (5 to 9 points), moderate (10 to 14 points) and severe (15 to 27 points).
For the anxiety symptoms, the Peruvian version of the GAD-7 (22) was used to assess the severity of anxiety symptoms. The GAD-7 delivers values in range between 0 and 21 points. The highest value indicates a higher anxiousness. This instrument was also validated in Peru with a representative sample (n = 2978), showing a good internal consistency (Cronbach's α = 0.89). This inventory defines also different categories for anxiousness: minimal (0 to 4 points), mild (5 to 10 points), moderate (11 to 15 points) and severe (16 to 21 points).
3.2.4 Statistical Analysis
Statistical analyses were performed using SPSS version 26.0 (Statistical Package for the Social Sciences, International Business Machines Corporation, New York, United States of America) and jamovi 1.2.5.0 (23). For the choropleth map of metropolitan Lima (figure 1), the software CARTODB (CARTODB Inc., Denver, United States of America) was used.
Descriptive data was managed with count data and percentages. To improve readability, the information was presented in tables. Quantitative variables approximately fitting a normal distribution are specified in the text as mean ± standard deviation (M ± SD), those with a non-normal distribution were expressed as median (Me) with percentile 75 (Q3) and percentile 25 (Q1) and the interquartile range (Q3 – Q1; IQR). Categorical variables were specified with count data and percentages. Data was rounded to the next decimal, in order to obtain results with two decimals. Values smaller than 0.001 were shown as < 0.001 and values greater than one million were expressed in scientific notation.
For the statistical model that explains the CPDI values of this sample size, an ordinal logistic regression was computed, considering the CPDI severity degrees as dependent variable. The best model, that explained the CPDI values, was chosen by using the Akaike information criterion (AIC). The following were picked up as predictor variables: age, GAD-7 scores, PHQ-9 scores, COVID_1, COVID_2, COVID_3, COVID_4, COVID_5, COVID_6, domicile, medication intake and previous medical disease. The results of this statistical modelling are presented in table 4. The odds ratio was flagged as “significant” if the two-tailed-p-value was smaller as 0.05. 95-percent confidence intervals were calculated for this model.