How likely is a false positive from a Covid test?

Positive thinking

The government wants us to test ourselves for Covid-19 twice a week, using lateral flow kits which will be freely distributed. What is the risk of being ordered to self-isolate as a result of a false negative?

— While the NHS claims that these tests produce false positives in 0.1% or fewer cases, an evaluation by Porton Down and Oxford University last year found a false positive rate of 0.3% in a hospital setting, rising to 0.39% in the community — in other words, about one in every 256 tests.

— According to the Office for National Statistics infection survey, in the week to 27 March one in every 370 people were infected (not necessarily showing symptoms) — 0.27% of the population.

— So for every 2 people who really do currently have the virus, you would expect 3 false positives.

Balance of power

The government set a target for 600,000 domestic heat pumps a year to be installed between now and 2028. Is England’s housing stock becoming any more energy efficient? Percentage of homes in each energy rating (with A being most efficient):

      Q4 2010    |    Q4 2020

A | 0.1 | 0.3

B | 13 | 15.4

C | 30.5 | 32.9

D | 32.6 | 36.6

E | 16.7 | 12

F | 5.3 | 2.1

G | 1.7 | 0.7

Source: Ministry of Housing, Communities and Local Government

Reality bites

An 85-year-old woman in Birmingham was killed by an escaped dog. Are deaths from dog bites increasing? Average number of annual deaths per decade:

1980s | 1.1

1990s | 1.6

2000s | 3.1

2010s | 3.5

The worst year was 2009, with 6 deaths. The last time 0 deaths were recorded was 1995.

Raising the bar

Pubs were allowed to reopen their gardens. Which features are considered essential among pubgoers? Prior to the pandemic:

Serves meals | 67%

Beer garden | 63%

Fireplace | 52%

Customers known by name | 51%

Serves snacks | 50%

Serves real ale | 37%

Live music | 35%

Background music | 35%

Source: YouGov