Table 3: Volume changes from 2017/18 to 2019/20
| Year | Total number of fees | Increase on previous year (number) | Increase on previous year (%) | Average Increase (%) |
|---|---|---|---|---|
| 2017-18 | 84,862,375 | n/a | n/a | n/a |
| 2018-19 | 85,325,559 | 463,184 | 0.546% | 1.160% |
| 2019-20 | 86,841,867 | 1,516,308 | 1.777% |
Source: NHS Prescription Services “Dispensing Doctors Report” and “Personal Administration Report” at https://www.nhsbsa.nhs.uk/prescription-data/dispensing-data/pd1-reports. Total number of prescriptions is the total in column D of each year from the Statistical Data Relating to Personal Administration Claims by Prescribing Doctors added to the totals A & B & C in column E for the Statistical Data Relating to Prescriptions Dispensed by Dispensing Doctors
Historical average annual volume change over last two years
Formula to calculate average percentage change over last two years is:
Total fees for 1st year x (1 + A) 2 = Total fees for the third year
Where A = annual percentage increase/decrease
84,862,375 x (1 + A) 2 = 86,841,867
(1 + A) 2 = 86,841,867 / 84,862,375
(1 + A) 2 = 1.0233
(1 + A) = √1.0233
(1 + A) = 1.0116
A = 1.0116 - 1
Therefore A = 0.0116
Average volume change over 2 years = 1.160 per cent
Note: The Geometric Mean has been used to calculate the average percentage change in fees. The Geometric Mean is a measure of the average value of a set of numbers by using the product of their values (as opposed to the arithmetic mean which uses their sum), and is calculated by multiplying all values together where n is the count of the number of values and then calculating the nth root.