Table 1. Logistic regression model for non-detection of neutralising antibodies, England, 22 April–12 May 2020 (n = 313).
| Factor | Categorisation | OR | 95% CI | p value |
|---|---|---|---|---|
| Age | Linear variablea | 0.96 | 0.93–0.99 | 0.002 |
| Hospitalised | Yes | Not done | Not done | 0.25 |
| No | ||||
| Ethnic group | Asian | Not done | Not done | 0.36 |
| Other | ||||
| Unknown | ||||
| White | ||||
| Gender | Female | 1 | Reference | 0.009 |
| Male | 0.41 | 0.21–0.80 | ||
| Donor centre | Edgware | Not done | Not done | 0.56 |
| Manchester | ||||
| Sheffield | ||||
| Tooting | ||||
| West End Donor Centre | ||||
| Other | ||||
| Blood group | A | 0.34 | 0.17–0.70 | 0.01 |
| B | 0.64 | 0.26–1.58 | ||
| O | 1 | Reference | ||
| AB | Excluded | Excluded | ||
| Previous blood donor | Yes | 0.36 | 0.11–1.16 | 0.06 |
| No | 1 | Reference | ||
| Social deprivation indicatorb | Affluent achievers | Not done | Not done | 0.98 |
| Rising prosperity | ||||
| Comfortable communities | ||||
| Financially stretched | ||||
| Urban adversity | ||||
| Days since project began | Linear variable | Not done | Not done | 0.42 |
| Days since diagnosis | Linear variablec | Not done | Not done | 0.97 |
CI: confidence interval; OR: odds ratio.
a A nonlinear term for age was tested but found to be non-significant (p = 0.9).
b Social deprivation scores were calculated based on postcode and Acorn classification [14], which divides the population into five categories. Based on that model, ‘affluent achievers’ are the most financially successful and healthy people in the United Kingdom, ‘rising prosperity’ includes generally younger, well educated, and mostly prosperous people living in our major towns and cities, ‘comfortable communities’ are the middle graders in terms of social and financial wellbeing, whereas the ‘financially stretched’ group includes mostly people with modest lifestyles and less than average income and the ‘urban adversity’ group includes people who are experiencing the most difficult social and financial conditions.
c A nonlinear term for ‘days since diagnosis’ was tested but found to be non-significant (p = 0.26).