Does Hydroxychloroquine work?

No seems to be the simple answer.

Observational Study of Hydroxychloroquine in Hospitalized Patients with Covid-19

(NEJM 7th May)

BACKGROUND

Hydroxychloroquine, widely used without robust evidence

Anti-inflammatory and antiviral effects

Food and Drug Administration, Emergency Use Authorization on March 30, 2020,

METHODS

Examined the association between hydroxychloroquine use and respiratory failure

Association between hydroxychloroquine use and intubation or death

New York–Presbyterian Hospital (NYP)–Columbia University Irving Medical Cente

1,446 consecutive patients

Tested positive for antigen

Compared outcomes, hydroxychloroquine or not

Hydroxychloroquine indicated in moderate-to-severe respiratory illness

Oxygen saturation of less than 94% on room air

RESULTS

1,376 patients followed up for 22.5 days

March 7 to April 8, 2020. Follow-up to April 25, 2020

811 (58.9%) received hydroxychloroquine

1,376 respiratory failure developed in 346 patients (25.1%)

180 patients were intubated, and 166 died without intubation

No significant association between hydroxychloroquine use and intubation or death

CONCLUSIONS

Hydroxychloroquine administration was not associated with either a greatly lowered or an increased risk of intubation or death

Findings do not support the use of hydroxychloroquine at present, outside randomized clinical trials testing its efficacy

Clinical guidance at our medical center has been updated to remove the suggestion that patients with Covid-19 be treated with hydroxychloroquine

Were Hydroxychloroquine-treated patients were more severely ill at baseline?

Adjusted for likely confounders,

Age

Race and ethnic group

Body-mass index

Diabetes

Chronic kidney disease

Chronic lung disease

Hypertension

Baseline vital signs

Oxygen therapy

Inflammatory markers

Unmeasured confounding may remain