Enrolment was suspended on 22may2020, after Mehra et al (Lancet 2020) then stopped due to lack of Covid19 cases.

Albertans with COVID-19 are at risk of deteriorating and developing severe illness. Those over age 40 or with co-morbid illness, and likely those who are immune suppressed, are at highest risk. This study will include a focus on people with immune-suppressed states. Individuals confirmed to have SARS-CoV-2 infection will be identified using administrative data (positive lab result, age 18 or over, not hospitalized, and not living in SL4 level of care). They will then be contacted by AHS staff, independent of the researchers, to obtain their consent for the researchers to contact them about this trial. The AHS staff member who contacts the individual will enroll consenting individuals into a study database. If they provided an email address an email will automatically be sent to the individual with study information. Those who decline to be contacted will also be informed of the study website so they can choose to review the study information and self-enrol, although they will need to do so quickly to meet study timelines. Enrolled participants will be contacted by a study coordinator. Those without access to the internet will be informed about the study details when they are contacted by a study coordinator. When the study coordinator contacts potential participants the study will be reviewed, and the potential participant will have an opportunity to ask questions. Consent for participation will be obtained by telephone. Telephone consent will be recorded. Participants will then be screened for inclusion and exclusion criteria by telephone interview and review of Alberta Netcare. Alberta Netcare is the province of Alberta's public Electronic Health Record used to store patient information so that it is easily accessible to healthcare professionals for the purpose of care. Information like immunizations, ECG results, diagnostic images and reports, written medical reports (e.g. surgery reports, consultations, hospital admissions), diagnostic lab testing results (e.g. blood tests, urine tests, blood bank info), allergies and intolerances (drug and food allergies, food intolerances), prescription history, and general patient information (e.g. name, birthdate, personal health number, address, phone number). Those who are not eligible for the study will be informed of the reason(s) for ineligibility (generally it will be a safety exclusion and they should be aware of this). Those who are eligible will be randomized to receive HCQ or placebo for a total duration of 5 days. Study drug will be delivered to their residence by courier. Telephone follow-up will occur at day 7 (range 7-10 days) and at day 30 (range 25-35 days).

This double-blind placebo-controlled, randomized clinical trial will determine if hydroxychloroquine for 5 days, initiated within 96 hours of confirmation of a positive COVID-19 result, and within 12 days of symptom onset, reduces the occurrence of severe COVID-19 disease. Severe disease is defined as the composite of hospitalization, invasive mechanical ventilation and 30-day mortality. This trial will enrol consenting adults who are not hospitalized, are age 18 or over, have a risk factor for severe disease, have no contraindication to treatment with hydroxychloroquine, can swallow pills, and who do not have a severe underlying comorbidity where treatment is not likely to be beneficial to the patient.

Secondary outcomes will be the proportion of participants requiring hospitalization, invasive mechanical ventilation, 30-day mortality, and disposition at 30 days, defined as recovered, ongoing symptoms but not hospitalized, hospitalized, or deceased.

Randomization will be stratified by age, risk of severe disease, and Alberta Health zone of primary residence. A pre-specified risk classification that includes immunosuppressed status will define those at high risk of severe disease. Health care delivery across Alberta Health zones will likely differ, in part due to the remote location of most patients in some zones.

Alberta has a single publicly funded health care system with processes and administrative data that will allow complete capture of health system encounters and resource utilization. The population is ethnically diverse. In 2016, 23.5% of Albertans belonged to a visible minority group compared with 22.3% for Canada overall (1). Also, in 2018, 94.1% of Albertans age 15 and older used the internet for personal use compared with 91.3% for Canada overall; this excluded full-time residents of institutions (2). This will support a high degree of electronic recruitment and data capture.

The current COVID-19 epidemic has also paused most ongoing research, thus providing access to many experienced researchers and highly trained research staff.

Lack of any proven treatments for this severe condition makes it imperative that we use the resources we have to try to improve the lives of Albertans and determine if there is evidence for the use of hydroxychloroquine for confirmed COVID-19 disease, overall, and in high risk participants.

Inclusion Criteria:

1. Confirmed SARS-CoV-2 infection, defined as RT-PCR provincial laboratory confirmation.
2. Self-reported symptoms of SARS-CoV-2 infection including any of the following: fever ≥37.5°C, cough, dyspnea, chest tightness, malaise, sore throat, myalgias, or coryza
3. Time from a positive test result to day 1 of treatment within 4 days
4. Time from patient reported first symptoms to day 1 of treatment within 12 days
5. Adults, age 18 and over, with any risk factor for severe disease
6. Resident of Alberta or if not a resident of Alberta able to provide complete follow-up data
7. Agrees to use adequate contraception for the duration of the study
8. Informed consent

Exclusion Criteria:

1. Currently or imminently planned admission to hospital

2. Any contraindication to hydroxychloroquine :

   1. Known hypersensitivity to hydroxychloroquine, chloroquine, or other 4-aminoquinoline derivatives, or any component of the formulation
   2. Known diagnosis of G6PD deficiency or porphyria
   3. Known retinal eye disease with vision impairment, in which hydroxychloroquine is a known contraindication
   4. Known history of QTc prolongation or QTc of > 470 msec (males) or > 480 msec (females) on any ECG within the previous year, if available
   5. Unexplained syncope or family history of long QT syndrome or family history of premature sudden cardiac death at < 50 years of age
   6. Severe diarrhea and/or vomiting or any eating disorders or any persistent vomiting condition
   7. Known significant liver disease including cirrhosis associated with any history of ascites, encephalopathy, or variceal bleeding as per history or medical chart (or Child Pugh B&C) or alcoholic hepatitis
   8. Uncontrolled epilepsy (more than 2 seizures within the previous year or any hospitalizations for status epilepticus within the previous 2 years)
   9. Current use of hydroxychloroquine (Plaquenil), chloroquine, lumefantrine, mefloquine, quinine, artemether, cyclosporine, dapsone, digoxin, and drugs that are known to prolong the QTc as per section 7.5.2.
   10. Score of 7 or more on the Tisdale scale modified such that instead of (1) admission potassium, any known serum potassium within the previous 30 days will be used; if no serum potassium is available the sub-score will be 0, and (2) admission ECG, any known ECG within the previous year will be used; if no ECG is available, the sub-score will be 0; (3) Use of HCQ will be included as one risk factor and anyone concurrently using a medication from the list of drugs known to prolong the QTc will already be excluded. (The other major risk factors for prolonged QTc are sepsis, heart failure, acute myocardial infarction, none of which are likely to be encountered in the outpatient setting).

3. Participation in an ongoing interventional clinical trial within the previous 30 days

4. Use of hydroxychloroquine (Plaquenil) or chloroquine, lumefantrine, mefloquine, or quinine within the previous 30 days.

5. Inability to swallow pills or any other reason that compliance with the medical regimen is not likely

6. Pregnant or breastfeeding

7. Severe underlying disease where treatment is not likely to be beneficial to the patient.

24 months after study close out.

pending.

A randomized, double-blind, placebo-controlled trial - trial staff and patients will all be blinded to the treatment allocation.