Estimation of the size of the COVID-19 pandemic using the epidemiological wavelength model: results from OECD countries

OBJECTIVES

This study aimed to simplify the previously developed epidemiological wavelength model and to expand the scope of the model with additional variables to estimate the magnitude of the COVID-19 pandemic. The applicability of the extended wavelength model was tested in Organisation for Economic Cooperation and Development (OECD) member countries.

STUDY DESIGN

The epidemiological wavelengths of OECD member countries for the years 2020, 2021 and 2022 were estimated comparatively, considering the cumulative number of COVID-19 cases.

METHODS

The size of the COVID-19 pandemic was estimated using the wavelength model. The scope of the wavelength model was expanded to include additional variables. The extended estimation model was improved by adding population density and human development index variables, in addition to the number of COVID-19 cases and number of days since the first case reported from the previous estimation model.

RESULTS

According to the findings obtained from the wavelength model, the country with the highest epidemiological wavelength for the years 2020, 2021 and 2022 was the United States (W_e = 29.96, W_e = 28.63 and W_e = 28.86, respectively), and the country with the lowest wavelength was Australia (W_e = 10.50, W_e = 13.14 and W_e = 18.44, respectively). The average wavelength score of OECD member countries was highest in 2022 (W_e = 24.32) and lowest in 2020 (W_e = 22.84). The differences in the periodic wavelengths of OECD countries were analysed with the dependent t-test for paired samples in two periods, 2020-2021 and 2021-2022. There was a statistically significant difference between wavelengths in the 2020-2021 and 2021-2022 groups (t(36) = -3.670; P < 0.001).

CONCLUSIONS

Decision-makers can use the extended wavelength model to easily follow the progress of the epidemic and to make quicker and more reliable decisions.

[Ulipristal acetate (Esmya): a selective modulator of progesterone receptors, new treatment of uterine fibromatosis]

Uterine fibromatosis is a frequent benign gynaecological disease causing heavy menstrual bleeding and in some cases anaemia. Until now, medical treatment aimed to obtain amenorrhea by administration of progestins or Gn-RH agonists. By inducing hypo-oestrogenism, a reduction of myoma size is observed with Gn-RH agonists but after cessation of the treatment, initial myoma size is noted. The impact of progesterone in myoma growth is nowadays demonstrated and use of selective modulators of progesterone receptors represents a new medical approach of this disease.

[Treatment of severe preeclampsia: until when and for what risks/benefits?]

The four major hypertensive disorders related to pregnancy are preeclampsia, chronic hypertension, preeclampsia superimposed upon chronic hypertension, and gestational hypertension. The development of hypertension and proteinuria in pregnancy is usually due to preeclampsia, particularly in a primigravida. These findings typically become apparent in the latter part of the third trimester and progress until delivery, but some women develop symptoms in the latter half of the second trimester, or intrapartum, or the early postpartum period. Preeclampsia is characterized as mild or severe. Severe hypertension, coagulopathy, thrombocytopenia, liver function abnormalities, and fetal growth restriction are features of severe disease. Laboratory evaluation should assess haemoglobin/hematocrit and platelet count, renal and hepatic function, as well as assessment of fetal well-being and growth. Timing of delivery is based upon gestational age, maternal and fetal condition, and the severity of preeclampsia. Maternal end organ dysfunction and nonreassuring tests of fetal well-being are indications for delivery at any gestational age. Antihypertensive treatment aims at protecting the mother from severe hypertensive encephalopathy, but may jeopardize the fetus. We recommend antenatal corticosteroids (betamethasone) be given to women with preeclampsia at 26 to 34 weeks of gestation. Magnesium sulfate is more effective than phenytoin for prevention of eclamptic seizures.