Correction: Is no test better than a bad test: Impact of diagnostic uncertainty on the spread of COVID-19.

[This corrects the article DOI: 10.1371/journal.pone.0240775.].

Is "no test is better than a bad test"? Impact of diagnostic uncertainty in mass testing on the spread of COVID-19.

Testing is viewed as a critical aspect of any strategy to tackle epidemics. Much of the dialogue around testing has concentrated on how countries can scale up capacity, but the uncertainty in testing has not received nearly as much attention beyond asking if a test is accurate enough to be used. Even for highly accurate tests, false positives and false negatives will accumulate as mass testing strategies are employed under pressure, and these misdiagnoses could have major implications on the ability of governments to suppress the virus. The present analysis uses a modified SIR model to understand the implication and magnitude of misdiagnosis in the context of ending lockdown measures. The results indicate that increased testing capacity alone will not provide a solution to lockdown measures. The progression of the epidemic and peak infections is shown to depend heavily on test characteristics, test targeting, and prevalence of the infection. Antibody based immunity passports are rejected as a solution to ending lockdown, as they can put the population at risk if poorly targeted. Similarly, mass screening for active viral infection may only be beneficial if it can be sufficiently well targeted, otherwise reliance on this approach for protection of the population can again put them at risk. A well targeted active viral test combined with a slow release rate is a viable strategy for continuous suppression of the virus.

Anti-VEGF intervention in neovascular AMD: benefits and risks restated as natural frequencies.

OBJECTIVE: Clear information is essential to properly determine preference in medical intervention. In neovascular age-related macular degeneration, patients need to understand the balance of risk and benefit of anti-vascular endothelial growth factor (VEGF) treatment. This balance is altered by the number of injections administered. METHODS: Natural frequencies, displayed as pictographically as icon arrays, are used to show material outcomes from the MARINA and HARBOR (12 months) trials. We also calculated the number needed to treat (NNT) and number needed to harm (NNH). RESULTS: MARINA 24-month data show the absolute risk reduction is 37% and the NNT is 3; meaning for one patient to benefit three need to be treated.12 months' HARBOR data show that compared with as-needed treatment, scheduled monthly injection treatment increases the number of patients achieving a better visual outcome. The number of patients suffering harm is also increased by the additional injections. CONCLUSION: Displaying MARINA and HARBOR trial data as natural frequencies, with numbers needed to treat and harm, communicates complimentary information on the positive and negative aspects of anti-VEGF treatment.

Changes to the law on consent following Montgomery vs Lanarkshire Health Board.

The Supreme Court's determination on Montgomery (AP) (Appellant) v Lanarkshire Health Board (Respondent) (Scotland) [2015] clarified UK law on consent. It is for the informed patient to determine which intervention, if any, they will undergo. All doctors must meet this standard and may need to reassess their practice to do so.