Estimating Drug Requirements - A Practical Manual: PART II: THE MORBIDITY METHOD: MODULE 7: The patient morbidity/standard treatment method: calculation procedures: 2. TASK 12: CALCULATING QUANTITIES REQUIRED OF EACH DRUG

Estimating Drug Requirements - A Practical Manual
(1995; 158 pages) [French] [Spanish]

Table of Contents

PREFACE
PART I: INTRODUCTION
	MODULE 1: Objectives and use of the manual
		1. INTRODUCTION
		2. THE TWO METHODS OF QUANTIFICATION
			2.1 The patient morbidity-standard treatment method
			2.2 The adjusted consumption method
		3. TARGET GROUP OF THE MANUAL
		4. OBJECTIVES OF THE MANUAL
		5. USING THE MANUAL
			5.1 Use for self tuition
			5.2 Use for courses
	MODULE 2: Assessing the need for better quantification
		1. SYMPTOMS OF POOR QUANTIFICATION
			1.1 Chronic and widespread shortages
			1.2 Surpluses
			1.3 Inequity of supply
			1.4 Inadequate cost-effectiveness
			1.5 Irrational adjustments to budgetary constraints
			1.6 Irrational and ineffective prescribing
			1.7 Suppression or distortion of demand
	MODULE 3: Preparing an action plan
		1. INTRODUCTION
		2. TASKS IN PREPARING AN ACTION PLAN
			2.A THE PREPARATORY PHASE
				TASK 1: Name the person responsible
				TASK 2: Form a working group for coordination
				TASK 3: Agree specific objectives
				TASK 4: Choose the quantification methods
				TASK 5: List tasks, estimate budget and obtain resources
				TASK 6: Programme tasks
				TASK 7: List health problems to be treated at facilities covered
				TASK 8: Select appropriate drugs for each health problem, in order to draw up essential drug list(s) for the facilities covered, and add packaging and price data
				TASK 9: Train staff in quantification methods
			2.B THE QUANTIFICATION PHASE
				TASKS 10-15: Data collection, quantification, costing, reconciliation to budget, calculation of final quantities per 1,000 cases
				TASK 16: Feed back results to managers for placing orders and allocating drugs to individual facilities
				TASK 17: Provide training in prescribing and stock management
				TASK 18: Evaluate the quantification process and make any necessary improvements
	MODULE 4: DRAWING UP AND REVIEWING ESSENTIAL DRUG LISTS BY TYPE OF FACILITY
		1. INTRODUCTION
		2. TASK 7-8: DECIDING LEVELS OF CARE AND ESSENTIAL DRUG LISTS BY TYPE OF FACILITY
		3. ADD PACK SIZE AND PRICE PER PACK
PART II: THE MORBIDITY METHOD
	MODULE 5: Data requirements: standard drug treatment schedules for quantifying requirements, based on average doses
		1. INTRODUCTION
		2. TASK 10: STANDARD DRUG TREATMENT SCHEDULES FOR QUANTIFYING DRUG REQUIREMENTS, BASED ON AVERAGE DOSES (AVERAGE DRUG TREATMENT SCHEDULES)
		3. GUIDELINES FOR DRAWING UP AVERAGE DRUG TREATMENT SCHEDULES
		4. ILLUSTRATIVE AVERAGE DRUG TREATMENT SCHEDULES FOR THE MIDDLE (HEALTH CENTRE) LEVEL OF CARE
	MODULE 6: Data requirement: morbidity data
		1. THE DATA REQUIRED - TREATMENT EPISODES
		2. TASK 11: DATA COLLECTION
			2.1 Estimates from centrally assembled patient morbidity data
			2.2 Estimate from morbidity data from a sample of health facilities
			2.3 Prospective sample survey
	MODULE 7: The patient morbidity/standard treatment method: calculation procedures
		1. INTRODUCTION
		2. TASK 12: CALCULATING QUANTITIES REQUIRED OF EACH DRUG
		3. TASK 13: ESTIMATING THE COST OF THE DRUG QUANTITIES REQUIRED
		4. TASK 14: RECONCILING DRUG QUANTITIES TO BUDGET
		5. TASK 15: CALCULATING AVERAGE DRUG REQUIREMENTS PER 1,000 TREATMENT EPISODES OR PER 1,000 PATIENT CONTACTS
PART III: THE CONSUMPTION METHOD
	MODULE 8: The adjusted consumption method: calculation procedure
		1. INTRODUCTION
		2. METHOD OF CALCULATION
		3. TASK 10: SELECT THE “STANDARD” FACILITIES WHOSE CONSUMPTION IS TO SERVE AS THE NORM FOR THE DRUG QUANTITIES TO BE SUPPLIED TO ALL FACILITIES OF THE SAME TYPE
		4. TASK 11: ESTIMATE THE NUMBER OF PATIENT CONTACTS AT ALL FACILITIES OF THE TYPE(S) CONCERNED
		5. TASK 12: CALCULATE THE AVERAGE DRUG USE PER 1,000 PATIENT CONTACTS AND THE QUANTITY REQUIRED OF EACH DRUG
ANNEXES
	Annex 1: Model record form for the community health worker
	Annex 2: Calculation sheet for drug quantities by health problem
	Annex 3: Calculation sheet for total quantities of each drug, number of order packs and cost
	Annex 4: Calculation sheet for total drug quantities and cost after reconciliation to budget, and quantities per 1000 treatment episodes
	Annex 5: Calculation sheet for recording drug quantities (consumption method)

2. TASK 12: CALCULATING QUANTITIES REQUIRED OF EACH DRUG

This task involves four steps:

STEP 1: Calculating the total quantity required of each drug for each health problem. To do this, multiply the number of treatment episodes during the year by the quantity of each drug required in that standard treatment.

STEP 2: Reorganize the quantities from step 1 above by drug to obtain the total quantity required of each drug. Where a drug is indicated for more than one standard treatment, add the quantities required for each one, to obtain the total.

STEP 3: Increase the quantities estimated in step two to allow for wastage and losses (damage, date expiry, loss, pilferage and theft).

STEP 4: Convert the quantities from step 3 into the required number of order packs.

STEP 1: Calculate the quantity of each drug required for each health problem.

EXAMPLE:

Suppose we wish to calculate the drug quantities required for village health workers, based on the average standard treatments specified in Table 5.1, and the number of treatment episodes in Table 6.6. The calculation sheet is shown in Table 7.1.

The first health problem (from Table 6.1) is acute diarrhoea (ICD 009.2). Six different standard treatments have been specified for this health problem (Table 5.1) but only severity 1 and severity 2 are to be treated by the village health worker. For severity 1 in children the average treatment is one packet of oral rehydration salts (ORS) to make one litre of fluid. The total number of treatment episodes among children requiring this treatment is 18,000 (from Table 6.6). So 18,000 packets of ORS are needed for these treatment episodes. For severity 2 acute diarrhoea in adults the average standard treatment is 6 packets of ORS and there are 10,800 treatment episodes. So the total quantity required for these treatments is 64,800 packets. The quantities for the other treatments are calculated in the same way.

EXERCISE 7A

1. Table 7.1 shows the number of treatment episodes and the average quantity of each drug required for the standard treatments of the first ten health problems from Table 6.6. The drug quantities required for each standard treatment have been calculated.

(a) Check that the average drug quantities per standard treatment, given in column 4 are correct (from the treatment schedules in Table 5.1).

(b) Check that the number of treatment episodes in column 5 are correct (from Table 6.6).

2. In column 2 of Table 7.1 the remaining health problems (from Table 6.6) are listed.

(a) In column 3, note the drug(s) specified in the standard treatment for each health problem, and in column 4 note the quantity of each drug per standard treatment (from Table 5.1).

(b) In column 5, note the number of treatment episodes of each standard treatment (from Table 6.6).

3. For each standard treatment multiply the number in column 4 by the corresponding number in column 5 to obtain the total quantity of each drug for each standard treatment.

Check your answers in Table 7.2.

Table 7.1: Calculation sheet for drug quantities by health problem

Abbreviations: S - Severity. A - Adults. C - Children. NEC - Not Elsewhere Classified
1	2	3	4	5	6
ICD Code	Health problem	Standard treatment Drug generic name, dosage form and strength	Quantity per standard treatment	Number of treatment episodes	TOTAL QUANTITY
009.2	Acute diarrhoea
	S1: A (no dehydration)	oral rehydration salts pkt (1 litre)	2 pkt	25200	50400
	S1: C (no dehydration)	oral rehydration salts pkt (1 litre)	1 pkt	18000	18000
	S2: A (some dehydration)	oral rehydration salts pkt (1 litre)	6 pkt	10800	64800
	S2: C (some dehydration)	oral rehydration sails pkt (1 litre)	2 pkt	14400	28800
084	Malaria (severity 1)
	S1: A	chloroquine tab 150 mg base	10 tab	65520	655200
	S1: C	chloroquine tab 150 mg base	2.5 tab	27600	69000
127.0	Ascariasis (roundworm) A+C	mebendazole tab 100 mg	6 tab	127200	763200
132	Pediculosis (lice) A+C	lindane cream 1% 25 g	1 tube	18000	18000
133.0	Scabies A+C	benzylbenzoate lot 25% (g)	60 ml	8400	504000
280	Iron deficiency anaemia
	A	ferrous sulfate tab 60 mg iron	84 tab	2400	201600
	C	ferrous sulfate tab 60 mg iron	28 tab	1200	33600
372.0	Conjunctivitis A+C	tetracycline eye oint 1% 5 g tube	1 tube	19200	19200
460	Common cold
	A	paracetamol tab 500 mg	8 tab	14400	115200
	C	paracetamol tab 500 mg	4 tab	12000	48000
521.0	Caries, toothache
	A	acetylsalicylic acid tab 300 mg	16 tab	20400	326400
	C	paracetamol 500 mg	4 tab	7200	28800
535-6	Gastritis, heartburn and indigestion A+C	aluminium hydroxide tab 500 mg	24 tab	13200	316800
564.0	Constipation
	A
	C
595	Cystitis
	S1: A
	S2: A
	S2: C
680-2	Boil, abscess
	A
	C
684	Impetigo, bacterial skin infection A+C
714-6	Arthritis & arthrosis
724	Back-pain, lumbago A
780.6	Fever NEC
	A
	C
780.7	Malaise, fatigue NEC
784.0	Headache NEC
	A
	C
786.2	Cough NEC
	A
	C
789.0	Abdominal pain NEC
	A
	C
840-8	Sprains and strains
	A
	C
910-19	Superficial injury, bruise, cut A+C
940-9	Burns
	A
	C
	TOTAL TREATMENT EPISODES
REPEAT VISITS FOR SAME HEALTH PROBLEM
	Injections
	A			20400
	C			8400
	Dressings
	A			30000
	C			13200
	Oral medication
	A			13200
	C			6000
	Follow-up visit
	A			9600
	C			4800
	TOTAL REPEAT VISITS			105600
OTHER HEALTH SERVICE CONTACTS
V03-06	Vaccinations
	A			20400
	C			72000
V20	Under-five preventive care
	C			69600
V22-3	Antenatal care
	A			84000
V25	Family planning, contraception
	A			103200
V70	Medical examination, no illness
	A			6000
	C			0
	TOTAL PREVENTIVE CONTACTS			355200
	GRAND TOTAL

Table 7.2: Calculation sheet for drug quantities by health problem (completed)

Abbreviations: S - Severity. A - Adults. C - Children NEC - Not Elsewhere Classified
1	2	3	4	5	6
ICD Code	Health problem	Standard treatment Drug generic name, dosage form and strength	Quantity per standard treatment	Number of treatment episodes	TOTAL QUANTITY
009.2	Acute diarrhoea
	S1: A (no dehydration)	oral rehydration salts pkt (1 litre)	2 pkt	25200	50400
	S1: C (no dehydration)	oral rehydration salts pkt (1 litre)	1 pkt	18000	18000
	S2: A (some dehydration)	oral rehydration salts pkt (1 litre)	6 pkt	10800	64800
	S2: C (some dehydration)	oral rehydration salts pkt (1 litre)	2 pkt	14400	28800
084	Malaria (severity 1)
	S1: A	chloroquine tab 150 mg base	10 tab	65520	655200
	S1: C	chloroquine tab 150 mg base	2.5 tab	27600	69000
127.0	Ascariasis (roundworm) A+C	mebendazole tab 100 mg	6 tab	127200	763200
132	Pediculosis (lice) A+C	lindane cream 1% 25 g	1 tub	18000	18000
133.0	Scabies A+C	benzylbenzoate lot 25% (g)	60 ml	8400	504000
280	Iron deficiency anaemia
	A	ferrous sulfate tab 60 mg iron	84 tab	2400	201600
	C	ferrous sulfate tab 60 mg iron	28 tab	1200	33600
372.0	Conjunctivitis A+C	tetracycline eye oint 1% 5 g lube	1 tube	19200	19200
460	Common cold
	A	paracetamol tab 500 mg	8 tab	14400	115200
	C	paracetamol tab 500 mg	4 tab	12000	48000
521.0	Caries, toothache
	A	acetylsalicylic acid tab 300 mg	16 tab	20400	326400
	C	paracetamol 500 mg	4 tab	7200	28800
535-6	Gastritis, heartburn and Indigestion A+C	aluminium hydroxide tab 500 mg	24 tab	13200	316800
564.0	Constipation
	A	senna tab 7.5 mg sennosides	2 tab	9600	19200
	C	senna tab 7.5 mg sennosides	0.5 tab	4800	2400
595	Cystitis
	S1: A	sulfamethoxazole & trimethoprim tab	4 tab	4800	19200
		400 mg & 80 mg
		paracetamol tab 500 mg	16 tab	4800	76800
	S2: A	sulfamethoxazole & trimethoprim tab	40 tab	2400	96000
		400 mg & 80 mg
	S1: C and S2: C: not applicable	paracetamol tab 500 mg	16 tab	2400	38400
	S2: C			0
680-2	Boil, abscess
	A	procaine benzylpenicillin 3 MU	0.33 vial	2400	792
		phenoxymethylpenicillin tab 250 mg	40 tab	2400	96000
		paracetamol tab 500 mg	8 tab	2400	19200
	C	procaine benzylpenicillin 3 MU	0.1 vial	1200	120
		phenoxymethylpenicillin tab 250 mg	10 tab	1200	12000
		paracetamol tab 500 mg	2 tab	1200	2400
684	Impetigo, bacterial skin infection A+C	neomycin/bacitracin oin (20 g)	1 tube	3600	3600
714-6	Arthritis & arthrosis	acetylsalicylic acid tab 300 mg	40 tab	4800	192000
724	Back-pain, lumbago A	acetylsalicylic acid tab 300 mg	40 tab	2400	96000
780.6	Fever NEC
	A	paracetamol tab 500 mg	8 tab	7200	57600
	C	paracetamol tab 500 mg	2 tab	10800	21600
780.7	Malaise, fatigue NEC	no drug		9600	0
784.0	Headache NEC
	A	acetylsalicylic acid tab 300 mg	8 tab	13200	105600
	C	paracetamol tab 500 mg	2 tab	1200	2400
786.2	Cough NEC
	A	chlorphenamine tab 4 mg	6 tab	15600	93600
	C	chlorphenamine tab 4 mg	3 tab	10800	32400
789.0	Abdominal pain NEC
	A	acetylsalicylic acid tab 300 mg	8 tab	6000	48000
	C	paracetamol tab 500 mg	2 tab	2400	4800
840-8	Sprains and strains
	A	acetylsalicylic acid tab 300 mg	8 tab	3600	28800
	C	paracetamol tab 500 mg	2 tab	1200	2400
910-19	Superficial injury, bruise, cut A+C	chlorhexidine sol conc 5% (ml)	1 ml	14400	14400
940-9	Burns
	A	chlorhexidine sol conc 5% (ml)	1 ml	4800	4800
		acetylsalicylic acid tab 300 mg	8 tab	4800	38400
	C	chlorhexidine sol conc 5% (ml)	1 ml	2400	2400
		paracetamol tab 500 mg	2 tab	2400	4800
	TOTAL TREATMENT EPISODES			544320
REPEAT VISITS FOR SAME HEALTH PROBLEM
	Injections
	A	The drug quantities needed far		20400
	C	these repeat visits are included		8400
	Dressings	in the quantities per treatment
	A	episode calculated in the first		30000
	C	section of the table.		13200
	Oral medication
	A			13200
	C			6000
	Follow-up visit
	A			9600
	C			4800
	TOTAL REPEAT VISITS			105600
OTHER HEALTH SERVICE CONTACTS
V03-06	Vaccinations
	A	Illustrative calculations have not		20400
	C	been done for these contacts		72000
V20	Under-five preventive care
	C			69600
V22-3	Antenatal care
	A			84000
V25	Family planning, contraception
	A			103200
V70	Medical examination, no illness
	A			6000
	C			0
	TOTAL PREVENTIVE CONTACTS			355200
	GRAND TOTAL			1005120

STEP 2: Reorganise the quantities from step 1 by drug, to obtain the total quantity required of each drug.

We now have the quantity of each drug required for each health problem. However, since many drugs are used for more than one standard treatment, we need to reorganize the results from Table 7.2 by drug. The calculation sheet for this is shown in Table 7.3.

EXAMPLE:

Taking the drugs in alphabetical order, the first one is acetylsalicylic acid tablets 300 mg. Reading through Table 7.2, this drug is used in seven standard treatments.
521.0	Caries and toothache (Adults)
714-6	Chronic arthritis and arthrosis (Adults)
724	Back pain and lumbago (Adults)
784	Headache (Adults)
789	Abdominal pain (Adults)
840-8	Sprains and strains (Adults)
940-9	Burns (Adults)
The code numbers of the health problems (and the severity and age group) are noted in Table 7.3, column 3, and the drug quantities are noted in column 4. As each one is noted, it is ticked off in Table 7.2. (The code numbers are recorded so that the quantities can still be related to the health problems for which they are required, and to make it easier to check that nothing has been omitted.)

EXERCISE 7B

Columns 3 and 4 of Table 7.3 have been completed for the first eleven drugs in alphabetical order.

1. Read through Table 7.2 for each of these drugs, and check that all the quantities for each one have been noted in Table 7.3.

2. For the remaining drugs on page 2 of Table 7.3 complete columns 3 and 4. Check your answers in Table 7.4.

Table 7.3: Calculation sheet for total quantities of each drug

1	2	3	4	5	6	7
Drug code number	Drug generic name, dosage form and strength	ICD code of health problem for which indicated & severity & age group	Total quantity for all standard treatments (in counting units)	Total quantity including allowance for wastage & loss	Order pack size = (number of units/ pack)	Number of packs required (rounded to the nearest whole number)
	acetylsalicylic acid tab 300 mg	521.0 A	326400
		714-6 A	192000
		724 A	96000
		784 A	105600
		789 A	48000
		840-8 A	28800
		940-9 A	38400
		TOTAL	835200 tab
	aluminium hydroxide tab 500 mg	535-6 A+C	316800 tab
	benzyl benzoate lot 25% (g)	133.0 A+C	504000 ml
	chlorhexidine sol conc 5% (ml)	910-19 A+C	14400
		940-9 A	4800
		940-9 C	2400
		TOTAL	21600 ml
	chloroquine tab 150 mg base	084 S1 A	655200
		084 S1 C	69000
		TOTAL	724200 tab
	chlorphenamine tab 4 mg	786.2 A	93600
		786.2 C	32400
		TOTAL	126000 tab
	ferrous sulfate tab 60 mg iron	280 A	201600
		280 C	33600
		TOTAL	235200 tab
	lindane cream 1% 25 g	132 A+C	18000
	mebendazole tab 100 mg	127.0 A+C	763200 tab
	neomycin/bacitracin oin (tube 20 g)	684 A+C	3600 tube
	oral rehydration salts pkt (1 litre)	009.2 S1: A	50400
		009.2 S1: C	18000
		009.2 S2: A	64800
		009.2 S2: C	28800
		TOTAL	162000 PKT
	paracetamol tab 500 mg
		TOTAL	tab
	phenoxymethylpenicillin tab 250 mg
		TOTAL	tab
	procaine benzylpenicillin inj 3 MU
		TOTAL	vial
	senna tab 7.5 mg sennosides
		TOTAL	tab
	sulfamethoxazole & trimethoprim tab 400 mg & 80 mg
		TOTAL	tab
	tetracycline eye oint 1% 5 g tube		tube
	TOTAL COST

Table 7.4: Calculation sheet for total quantities of each drug (completed)

1	2	3	4	5	6	7
Drug code number	Drug generic name, dosage form and strength	ICD code of health problem for which indicated & severity & age group	Total quantity for all standard treatments (in counting units)	Total quantity including allowance for wastage & loss	Order pack size = (number of units /pack)	Number of packs required (rounded to the nearest whole number)
	acetylsalicylic acid tab 300 mg	521.0 A	326400
		714-6 A	192000
		724 A	96000
		784 A	105600
		789 A	48000
		840-8 A	28800
		940-9 A	38400
		TOTAL	835200 tab	876960
	aluminium hydroxide tab 500 mg	535-6 A+C	316800 tab	332640
	benzyl benzoate lot 25% (g)	133.0 A+C	504000 ml	529200
	chlorhexidine sol conc 5% (ml)	910-19 A+C	14400
		940-9 A	4800
		940-9 C	2400
		TOTAL	21600 ml	22680
	chloroquine tab 150 mg base	084 S1 A	655200
		084 S1 C	69000
		TOTAL	724200 tab	760410
	chlorphenamine tab 4 mg	786.2 A	93600
		786.2 C	32400
		TOTAL	126000 tab	132300
	ferrous sulfate tab 60 mg iron	280 A	201600
		280 C	33600
		TOTAL	235200 tab	246960
	lindane cream 1% 25 g	132 A+C	18000	18900
	mebendazole tab 100 mg	127.0 A+C	763200 tab	801360
	neomycin/bacitracin oin (tube 20 g)	684 A+C	3600 tube	3780
	oral rehydration salts pkt (1 litre)	009.2 S1: A	50400
		009.2 S1: C	18000
		009.2 S2: A	64800
		009.2 S2: C	28800
		TOTAL	162000 PKT	170100
	paracetamol tab 500 mg	460 A	115200
		460 C	48000
		521.0 C	28800
		595 S1: A	76800
		595 S2: A	38400
		680-2 A	19200
		680-2 C	2400
		780.6 A	57600
		780.6 C	21600
		784-0 C	2400
		789.0 C	4800
		840-8 C	2400
		940-9 C	4800
		TOTAL	422400 tab	443520
	phenoxymethylpenicillin tab 250 mg	680-2 C	96000
		680-2 A	12000
		TOTAL	108000 tab	113400
	procaine benzylpenicillin inj 3 MU	680-2 A	792
		680-2 C	120
		TOTAL	912 vial	957.6
	senna tab 7.5 mg sennosides	564.0 A	19200
		564.0 C	2400
		TOTAL	21600 tab	22680
	sulfamethoxazole & trimethoprim tab 400 mg & 80 mg	595 S1: A	19200
		595 S2: A	96000
		TOTAL	115200 tab	120960
	tetracycline eye oint 1% 5 g tube	372.0 A+C	19200 tube	20160
	TOTAL COST

STEP 3: Increase the quantities estimated in step 2 to allow for wastage and losses.

The quantities in Table 7.4 are strictly those required to treat the estimated patient morbidity. In practice, there is also a certain amount of wastage through damage, date expiry, and loss through pilferage and theft. This needs to be allowed for.

EXAMPLE:

In Table 7.4 column 5, all the quantities estimated in column 4 have been increased by 5% as an allowance for wastage and loss.

The above example is of course simplified. In practice it is advisable to make separate adjustments for each dosage form. For example, liquid forms in large bottles may be subject to more wastage (through breakages) than solid dosage forms.

Specific adjustments may be needed for particular drugs or groups of drugs with higher or lower than average wastage and loss. For example, dapsone tablets for leprosy are less likely to be pilfered than antibiotics or antimalarials.

STEP 4: Convert the quantities from step 3 into the required number of order packs.

The quantities we have are still expressed in counting or prescribing units, but drugs are ordered and delivered in packs. We must therefore translate these quantities into numbers of order packs. To do this we need to know pack size, that is the number of counting units per pack. The number of order packs required is given by the formula:

EXAMPLE:

In Table 7.4 the quantity of 300 mg acetylsalicylic acid tablets estimated to be required is 876,960 tablets. Referring back to the drug list in Table 4.8 we find that these tablets are supplied in tins of 1,000 tablets. The number of order packs required is therefore 876,960/1,000 = 877 (the number of packs is rounded up to the next whole number).

EXERCISE 7C:

In Table 7.4 insert the order pack size for each drug (from Table 4.8), in column 6. For each drug, divide the total in column 5 by the corresponding pack size in column 6, to find the number of packs. Note the results in column 7. Round up the answer to the next whole number. Check your answers in Table 7.5.