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How we process prescriptions

We use high speed scanners and intelligent character recognition software to read the information we need to pay you, including:

  • quantity
  • strength
  • presentation
  • patient exemption information.

We reimburse and remunerate contractors in line with the rules set out in the Drug Tariff

Operator involvement

Our calculation software is designed to automatically process items where the Drug Tariff rules are straightforward and don’t need any endorsement information. Items that you need to endorse, such as 'No Cheaper Stock Obtainable' items or products like Fortisip when assorted flavours are prescribed, information from handwritten prescriptions and referred back items and any information that can’t be automatically read confidently is sent to an operator for processing. Once we have captured all the information we need, the information is sent through the calculation software for pricing.

If we need further information we’ll send the prescription back to you before we pay for that item.

Our accuracy

NHS Prescription Services process approximately 1.1 billion prescription items per year, dispensed within a primary care setting in England. The processed data is used to pay dispensing contractors and to provide prescribing information to the Department of Health and NHS. A statistically valid random sample of 50,000 of these prescription items is reprocessed on a monthly basis to estimate the accuracy of prescription processing.  
View the latest accuracy measure charts.

Prescription Processing Information Accuracy (PPIA)

This measure reflects the accuracy of processed information as it impacts the provision of prescribing information. It measures the number of items sampled that were processed accurately as a proportion of the number of items sampled. The target for this measure expects that 99.0%of all items should be processed accurately.

PPIA = Number of accurate items in the 12 month rolling period/Number of items sampled in the 12 month rolling period (600k).

This value is expressed as a %.

Prescription Processing Payment Accuracy (PPPA)

This measure reflects the accuracy of processed information as it affects the payments made to dispensing contractors.  It measures the number of items sampled that were processed accurately as a proportion of the number of items sampled. The target for this measure expects that 99.1% of all items should be processed financially accurate.

PPPA = Number of financially accurate items in the 12 month rolling period/Number of items sampled in the 12 month rolling period (600k)

This value is expressed as a %

Net Cash Variance (NCV)

NCV reflects the accuracy of the overall drugs bill in terms of that dispensed in a primary care setting (and consequently the payment made to dispensing contractors). The measure calculates the difference between the value actually paid against the corrected value of the items as a proportion of the value actually paid against the items sampled. Some errors will be overpayments and others will be underpayments, the NCV measure nets off under and overpayments. A negative NCV indicates an underpayment and a positive NCV indicates an overpayment. Ideally, the measure should be as close to 100% as possible, but with a tolerance of +/- 0.2%.

NCV = 1- (Sum of monthly NET error values in the 12 month rolling period/Sum of the monthly value of items sampled for the 12 month rolling period)

This value is expressed as a %.

Accuracy of Absolute Cash Variance (ACV)

Where NCV nets off underpayments against overpayments, ACV aggregates under and overpayments.  

The ACV is 1-(the sum of the absolute error values (for all items sampled) as a proportion of the value actually paid against the items sampled) expressed as a percentage. Therefore, this measure provides an absolute monetary indication of the financial accuracy of prescription processing. Variance against ACV will always be wider than NCV.  From March 2013 the target for this measure was increased to 99.30% of the total value paid to contractors.

NOTE: ‘Absolute’ indicates all values are positive.  For example, the absolute value of £2.34 is £2.34; but the absolute value of £-2.34 is also £2.34.

ACV = 1- (Sum of the monthly absolute error values in the 12 month rolling period/Sum of the monthly value of items sampled for the 12 month rolling period)

This value is expressed as a %.