Table 3.

Higher circulating OPN levels, female gender, higher BMI and pre-existing exertional dyspnea (m-MRC > 1) are associated with serious post-acute COVID-19 sequelae during follow-up visits after hospitalization for acute disease.

		Dependent Variable: Serious Symptom Combination			Dependent Variable: Dyspnea with m-MRC > 1
Parameter Estimates	Variable	Adjusted OR	95% CI	p-Value	Adjusted OR	95% CI	p-Value
β0	Intercept	4.08	0.41–43.45	0.23	0.04	0.001–1.17	0.08
β1	OPN (ng/μl)	1.02	0.99–1.05	0.22	1.05	1.004–1.09	0.03
β2	Age(y)	0.97	0.93–1.01	0.11	1.01	0.95–1.08	0.8
β3	Male gender	0.2	0.09–0.41	<0.001	0.3	0.098–0.86	0.03
β4	BMI ≥ 30 (kg/m2)	2.21	1.09–4.6	0.03	1.69	0.57–5.19	0.3
β5	CCI > 2	2.19	0.83–6.01	0.12	1.28	0.29–5.91	0.7
β6	Non-severe acute illness	0.79	0.33–1.83	0.59	1.53	0.43–4.97	0.5
β7	Pre-existing m-MRC > 1	2.84	0.67–15.08	0.18	71.22	10.5–1517	<0.001

Two multiple logistic regression models were developed using patient characteristics and measurements obtained during follow-up visits. Plasma OPN levels were considered as the independent variable and serious symptom combination or m-MRC > 1 were considered as the dependent variables. Age, gender, BMI, CCI, COVID-19 severity (according to WHO) during hospitalization and pre-hospitalization dyspnea with m-MRC > 1 were treated as covariates. AU-ROC curve for the first model was 0.76 (95% CI = 0.68–0.84, p < 0.001) and for the second one was 0.85 (95% CI = 0.75–0.94, p < 0.001). Estimates are presented as adjusted odds ratio (OR) and p-values <0.05 were considered significant. Serious symptom combination is defined as the presence of at least one of the following: dyspnea, fatigue and muscular weakness. OPN: osteopontin, m-MRC: modified Medical Research Council dyspnea scale, BMI: body mass index, CCI: Charlson comorbidity index, non-severe acute illness (WHO): no need for supplemental oxygen during hospitalization, WHO: World Health Organization, 95% CI: 95% confidence interval, AU-ROC curve: area under the receiver-operating characteristic curve.