ANTIBIOTIC USE AND COST TRENDS

2. ANTIBIOTIC USE AND COST TRENDS

Most information available comes from industrialised countries with minimal data from the developing world. In the United States, antimicrobial prescription rates by office-based physicians remained unchanged from 1980 through 1992; however, prescriptions for children increased by 48% (McCaig and Hughes, 1995). A large portion of these prescriptions was for the treatment of colds, upper respiratory tract infections, and bronchitis—conditions where there is no proven benefit of antibiotic therapy. Trends in antimicrobial pre- scribing at visits to office-based physicians, hospital outpatient departments, and hospital emergency departments from 1992 to 2000 in the United States declined by 25% (McCaig et al., 2003). Amoxicillin and the cephalosporins were most prescribed (annual drug prescription rate per 1,000 population) in outpatient settings between 1980 and 1992 (McCaig and Hughes, 1995; Steinman et al., 2003). Even though antibiotic use in ambulatory patients is decreasing, use of broader-spectrum antimicrobial drugs increased from 24% to 48% in adults and from 23% to 40% in children (Figures 1 and 2). The cost of broad-spectrum antibiotics exceeded $50 for a typical 7-day adult course (Steinman et al., 2003).

The overall profile of antibiotic use in Australia by drug class was similar to that in the United Kingdom with the majority of antibiotics being prescribed in outpatient and community settings (Beilby et al., 2002). Antibiotic use in Australia remained steady between 1990 and 1995, with an estimated 24.7 DDDs/1,000 population/day dispensed through community pharmacies in 1990 and 24.8 DDDs/1,000 population/day in 1995. Amoxicillin, although declining in use, remained the most dispensed antibiotic (McManus et al., 1997). Each year Australia imports about 700 tons of antibiotics; one third of this is destined for human use and the remaining two thirds for use in animals. Australia is one of the world’s highest users per capita of oral antibiotics (Geue, 2000), with the majority of these prescriptions originating from hospi- tals (South et al., 2003).

For 1987–92, drug expenditure in Thailand increased at around 23% per annum, higher than the growth rate of health expenditure (14%) and GNP (8%). In 1993 drug consumption cost 50,000 million Baht (US$1,164.63) or 840 Baht (US$19.56) per capita (Riewpaiboon et al., 1997).

After more than a decade of increasing antibiotic consumption in Chile, physicians became alarmed by the associated economic costs as well as rising antibiotic resistance due to indiscriminate use of these drugs (Salvatierra- Gonzalez and Benguigui, 2000). A study compared antibiotic consumption in Chile over a 10-year period from 1988 to 1998. Antibiotic consumption was measured as defined daily doses (DDD)/1,000 inhabitants/day (WHO, 1996a). The results showed a marked increase in consumption for most antibiotics

Antibiotic Policies in Developing Countries 595

80 Narrow spectrum Broad spectrum

Adult Office Visits That Resulted in Antibiotic Prescriptions, %

1991–1992 1994–1995 1998–1999 1991–1992 1994–1995 1998–1999 1991–1992 199 1998–1999 1991–1992 1994–1995 1998–1999 1991–1992 1994–1995 1998–1999 1991–1992 1994–1995 1998–1999 Common Cold

Acute UTI + URTI

Bronchitis (9 million

Media

(10 million (7 million visits/y)

visits/y)

visits/y)

visits/y)

visits/y) visits/y)

Figure 1. Antibiotic prescribing among adults between 1991–2 and 1998–9. Notes: Overall use of antibiotics decreased in adult visits for the common cold and unspecified

upper respiratory tract infections (URTIs) (P ⫽ 0.011), for pharyngitis (P ⫽ 0.02), and for acute bronchitis (P ⬍ 0.001). Among adults receiving an antibiotic, broad-spectrum agents made up an increased proportion of antibiotic prescriptions for each condition shown (for pharyngitis, P ⫽ 0.002; for all other conditions, P ⬍ 0.001). (Results are shown at the level of the patient visit: Broad spectrum indicates visits involving at least one broad-spectrum antibiotic; narrow spectrum indicates visits involving only narrow-spectrum agents.) The mean number of visits occurring annually during the study period is shown for each condition. UTI ⫽ urinary tract infection.

Source: Reproduced with permission of American College of Physicians.

The analysis of 10 years of antibiotic consumption showed that while many antibiotics were being sold, the most dramatic increases were seen in the sales of amoxicillin (498%), amoxicillin–clavulanic acid (16,460%), cephalosporins (309%), and fluoroquinolones (473%). The cost to the Chilean population for these drugs totalled US$45.8 million in 1997 (Table 2). Three months later, a second antibiotic consumption study evaluated the impact of the enforced measure. A 3-month period in 1999 was compared with the same 3-month period of 1998 (Table 3). Researchers found that ampicillin consumption decreased by 53%, amoxicillin by 36%, and erythromycin by 30%. Sales of antibiotics dropped by US$6.5 million, with no adverse patient outcomes

596 Aníbal Sosa

80 Narrow spectrum

70 Broad spectrum

Adult Office Visits That Resulted in Antibiotic Prescriptions, %

1991–1992 1994–1995 1998–1999 1991–1992 1994–1995 1998–1999 1991 1994–1995 1998–1999 1991–1992 1994–1995 1998–1999 1991–1992 1994–1995 1998–1999 Common Cold

Acute + URTI

Bronchitis (12 million

Media

(4 million visits/y)

visits/y)

visits/y)

visits/y)

visits/y)

Figure 2. Antibiotic prescribing among children between 1991–2 and 1998–9. Notes: Overall use of antibiotics decreased in paediatric visits for the common cold and

unspecified URTIs (P ⬍ 0.001) and for pharyngitis (P ⫽ 0.002). Among children receiving an antibiotic, broad-spectrum agents made up an increased proportion of antibiotic prescrip- tions for each condition shown (for P values, see text). (Results are shown at the level of the patient visit: Broad spectrum indicates visits involving at least one broad-spectrum antibi- otic; narrow spectrum indicates visits involving only narrow-spectrum agents.) The mean number of visits occurring annually during the study period is shown for each condition.

Source: Reproduced with permission of American College of Physicians.

Table 1. Comparison of antibiotic consumption in Chile over 10 years Antibiotic

1988 a 1997 a % change Cloxacillin

0.39 0.417 7 Ampicillin

0.54 0.613 14 Amoxicillin

0.87 5.204 498 Amoxicillin–Clavulanic acid

0.281 473 a DDD/1,000 inhabitants/day.

Antibiotic Policies in Developing Countries 597

Table 2. Antibiotic sales in 1988, 1996, and 1997 Antibiotic group

1988 a 1996 a 1997 a Macrolides

10,790,383 14,745,019 BS b penicillin

11,606,151 13,869,812 NS c penicillin

37,603,688 45,874,648 a In US dollars.

b BS: Broad spectrum. c NS: Narrow spectrum.

Table 3. Recent antibiotic consumption in Chile during a 1-year period Antibiotic

Fourth quarter % change 1998 a 1999 a

0.182 ⫺53.4 Amoxicillin–Clavulanic Acid

0.340 ⫺31.8 a DDD/1,000 inhabitants/day.

Table 4. Antibiotic sales in 1998 and 1999 Antibiotic group

1998 a 1999 a Macrolides

12,448,627 BS penicillin

11,227,954 NS penicillin

37,030,819 a In US dollars.

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