Table 3b.

Example of calculating the PPG score for a vaccine hesitancy fanning belief

	Belief: “Vaccination could permanently alter my DNA.
		Strong disbelievers (=Strongly disagree/somewhat disagree)	Potential disbelievers (=all other responses)	Overall
Whole sample	% Vaccine acceptance = 1	83.3%	17.0%	79.1%	PPG = 83.3–79.1 = 4.2%
	% Disbelievers in targeted population	94.8%	5.2%
Urban	% Vaccine acceptance = 1	87.0%	12.7%	83.6%	PPG = 87.0–83.6 = 3.4%
	% Disbelievers in targeted population	95.8%	4.2%
Rural	% Vaccine acceptance = 1	80.4%	17.3%	77.0%	PPG = 80.4 – 77.0 = 3.4%
	% Disbelievers in targeted population	94.3%	5.7%
Clinical staff	% Vaccine acceptance = 1	85.6%	8.5%	82.0%	PPG = 85.6–82.0 = 3.6%
	% Disbelievers in targeted population	95.8%	4.2%
Non-clinical staff	% Vaccine acceptance = 1	81.1%	22.6%	76.5%	PPG = 81.1–76.5 = 4.6%
	% Disbelievers in targeted population	93.9%	6.1%

Notes. For the whole sample, the conditional probability of being vaccine endorsers (i.e., vaccine acceptance = 1) among the strong dis-believers (i.e., strongly disagree or somewhat disagree with the belief item) was estimated to be 83.3%. The conditional probability of being vaccine endorsers among the potential disbelievers (i.e., reporting lower levels of disagreement with the belief item) was estimated to be 17.0%. The marginal probability of being vaccine endorsers in the targeted population—which, in this case referred to the entire sample—was estimated to be 79.1%. Then, for the whole sample, the PPG score was calculated as 83.3%−79.1% = 4.2%.

In this example, the total proportion of strong disbelievers in the whole sample was estimated to be 94.8% and the corresponding estimated proportion for potential disbelieves was 5.2%. These proportions were informative but not necessary for calculating the PPG score. For other sub-groups (urban, rural, clinical staff, non-clinical staff), targeted PPG scores were provided following the same formula.