Impact of an essential drugs list and treatment guidelines on prescribing in South Africa. Pillay T, Hill SR University of Newcastle

Background National Drug Policy identifies the need for an Essential Drugs Programme. EDL and Standard Treatment Guidelines published in 1998. No evaluation of prescriber compliance with the guidelines. Pilot studies suggest that prescribers do not follow the hypertension guidelines.

Approaches to measuring compliance with guidelines? Database of prescriptions – public sector in SA does not capture prescription electronically. Indicators Monitoring National Drug Policy-rational use indicators require prescription survey Assessing drug use at facilities require prescription survey.

Problems with prescription surveys for this study How do you choose which hospitals to survey prescriptions? There are 60 hospitals (urban and rural) in the province of KZN. Prescription survey will be time consuming. Requires financial and human resources.

Can we use aggregate purchases data? Defined daily dose (Nordic) Average daily quantity (UK) Equipotent dose (Danish) Minimum marketed dose Prescribed daily dose All of the above are fairly similar however they are all based on average dsing in other countries.

Alternative approach in resource poor settings Use patients ready packs as the measure of drug use. Advantages: Does not reply on the average dose prescribed in Nordic countries More accurate reflection of the exact quantity of drug dispensed to a patient over a 28 day period. Allows for variation in dosage Unit of issue ex-manufacturer

Application of methodology in hypertension Calculate the total number of PRPs issued for each drug over a 6 month period. Add up the total number of PRPs for each dug class ie all diuretics, beta blockers, ACEI. Then obtain a total for PRPs all antihypertensive drugs.

Prescription survey to validate drug supply data 16 hospitals selected from the three categories of methyldopa use (low, moderate and high) for survey. urban and rural hospitals. 100 prescriptions presented to the outpatient pharmacy department for the management of uncomplicated essential hypertension. The prescriptions were analysed to determine: whether supply data and prescription data were similar the proportion of each antihypertensive class, monotherapy and combination therapy, the doses prescribed

What should we expect if prescribers followed the hypertension guidelines? The trend in proportional use (highest to lowest) Diuretics Reserpine Beta blockers ACEI Calcium channel blockers

What did we find?

Which hospitals are using large volumes of methyldopa?

How does the prescription survey compare with the estimates from the supply data Level of Use Standard treatment guideline Estimated use from the supply data as proportional use Prescription Survey expressed as proportional use Prescription Survey expressed as no. of drugs per 100 prescriptions 1st Line Diuretic Diuretics 42% Diuretics 44% Diuretics 85% 2nd Line Reserpine ACEI 27% ACEI 30% ACEI 58% 3rd Line Beta blocker Methyldopa 10% CCB 12% CCB 24% 4th Line ACEI Reserpine 7% Beta blocker 7% Beta blocker 13% 5th Line CCB Beta blocker 6% Methyldopa 5% 6th Line Alpha Blocker CCB 6% Reserpine 3% Reserpine 5%

Conclusions “Patient ready packs” provides a useful alternative method for estimation of drug use. Supply data analysis and the prescription survey results are similar. Probably most useful for chronic diseases

Conclusions The general prescribing trend suggests that prescribers do not follow the guidelines. Methyldopa is widely prescribed at certain hospitals in the province. ACEI are used as 2nd line add therapy. Beta blockers are not widely prescribed even though there is good evidence to support their use and they are cheaper.