Table 4. Parsimonious model of the multiple ordinal logistic regression*¹.

	Level	OR	[95% CI]	p-value
Age	Continuous	1.003	[0.996; 1.010]	0.45
Sex	Female	1.805	[1.454; 2.241]	< 0.001
	Male	Reference
Education level*2	Metric	1.147	[1.057; 1.245]	0.001
Nursing home resident	Yes	0.087	[0.046; 0.165]	< 0.001
	No	Reference
SCQ-D*3	Continuous	1.096	[1.058; 1.137]	< 0.001
Hospitalized during acute COVID-19*4	Yes	2.014	[1.538; 2.637]	< 0.001
	No	Reference
Need for analgesics during acute COVID-19*5	Yes	1.704	[1.186; 2.446]	0.004
	No	Reference

*¹ Parsimonious model after stepwise backward selection of the potential predicting variables for post-COVID-19. The outcome variable comprised three categories (1, no symptoms; 2, symptom duration < 12 weeks; 3, symptom duration = 12 weeks) with post-COVID-19 (symptom duration ≥ 12 weeks) as response (n = 1459; imputed data set with 500 imputations).

*² Only one parameter was estimated in a linear coding of the six different educational levels.

*³ Interpretation of the OR: with each increase of one point on the 45-point scale of the SCQ-D, the likelihood of developing post-COVID-19 rises by 9.6%. In other words, the higher the overall burden of ?comorbidities (measured on the SCQ-D), the greater the likelihood of developing post-COVID-19.

*⁴ Interpretation of the OR: Study participants who had to be hospitalized for treatment during the acute phase of COVID-19 have a 2.01 times greater likelihood of developing post-COVID-19 than those who were not hospitalized. In other words, their risk of developing post-COVID-19 is 101% higher.

*⁵ Interpretation of the OR: Study participants who had to take analgesics during the acute phase of COVID-19 had a 1.7 times greater likelihood of developing p ost-COVID-19 than those who did not have to take analgesics. In other words, their risk of developing post-COVID-19 is 70% higher. This does not mean that the consumption of analgesics causes the higher risk; rather, it is a surrogate for the severity of the acute disease.

95% CI, 95% confidence interval; OR, odds ratio;

SCQ-D, Self-Administered Comorbidity Questionnaire, German version