A Cross-Sectional Comparative Analysis of Long Covid Symptoms in a Primary Care Population

CONTEXT: Long Covid presents with many symptoms that are highly prevalent in primary care. Most studies of long Covid have focused on selected populations, and have not compared symptom prevalence to a general primary care population.

OBJECTIVE: Compare the prevalence of long covid symptoms in primary care patients who have had and have not had COVID-19.

STUDY DESIGN: Online survey sent to those with and without a previous diagnosis of COVID-19. We asked both groups whether they had any symptoms of long covid in the past month, which was at least a month after any positive COVID-19 test. The surveys were sent in the summer of 2021. The population consisted of primary care patients of a national membership-based primary care delivery system, operating in several metropolitan locations in the US. We sent invitations to participate to 22,620 patients, from positive-test, negative-test and no-test groups, that were matched for age, sex, region, Covid test date, and Covid testing frequency. We received 947 responses (4.2% response rate).

SETTING/POPULATION: Primary care patients of a national membership-based primary care delivery system, operating in several metropolitan locations in the US.

INSTRUMENT: Online survey.

MAIN OUTCOME MEASURE: Prevalence of symptoms, compared between those with and without a previous self-reported diagnosis of Covid.

RESULTS: Using factor analysis and clinical criteria we grouped symptoms into categories. Propensity score matching was used to rebalance the groups of respondents. The prevalence of sensory symptoms (i.e. taste and smell changes) were higher in the group that tested positive for COVID-19 than the group that tested negative (17.4% [95% CI: 13.4%, 21.4%] vs. 8.5% [5.6%, 11.5%], p<0.001). No other symptom group, including cardiac, respiratory, neuro-cognitive, or pain showed any differences in prevalence between those patients with and without a history of COVID-19.

CONCLUSIONS: In contrast to other studies which have shown high prevalence of various symptoms in patients with long covid, this study found that only sensory changes were more prevalent in patients who had recovered from covid.