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The New Zealand Medical Journal

 Journal of the New Zealand Medical Association, 21-November-2003, Vol 116 No 1186

Prescribing for teenagers in New Zealand general practice
Jason Hall and Isobel Martin
Abstract
Aim To describe patterns of prescribing in general practice for New Zealanders aged 13 to 19 years.
Methods The computerised records of 225 348 consulting patients from 48 general practices from around New Zealand were examined. A subset of 20 216 consulting patients (53.2% female) aged 13 to 19 years was selected and their prescribed medications analysed. General practice prescribing was described in terms of demographic characteristics and health-card eligibility.
Results Patients aged 13 to 19 consult and are prescribed to less than the population as a whole (3.2 consultations versus 5.0, and 2.4 scripts versus 4.9 per annum). Females were prescribed to more frequently than males (2.7 prescriptions per consulting patient per annum versus 2.0). Patients with a community services card were prescribed to more frequently than those without (2.9 prescriptions per consulting patient per annum versus 2.0). Respiratory drugs were most frequently prescribed (primarily anti-asthma medications), followed by medications for the treatment of infections, the genito-urinary system (mainly oral contraceptives), dermatological medications, and medications for treatment of the nervous system (mainly analgesics).
Conclusions Patients aged 13 to 19 consult and are prescribed to less frequently than the population as a whole. Asthma appears to be the major source of chronic illness for this population. Prescribing data presented here provide valuable baseline data for further research.

There is a paucity of literature on prescribing for teenagers compared with that of prescribing for other populations. It has been suggested that as teenagers do not conveniently fall into any current medical specialty, their healthcare is particularly relevant to primary care.1 Although teenagers tend not to have the chronic diseases (asthma aside) that affect adults and older people, there are many challenges in the healthcare of teenagers involving management of the risk of health-damaging behaviours such as smoking, pregnancy, and drug and alcohol use.2 Emotional health issues are also extremely important. A recent investigation of New Zealand secondary school students found a high prevalence of significant depressive symptoms, eating issues and suicidal behaviours, especially amongst females.3
Youth health is seen as an important part of the Government’s health policy as reflected in its document ‘Youth health: a guide to action’.4 It is now recognised that teenagers are a distinct demographic group with specific healthcare needs. Despite evidence of reservations amongst young patients about using primary healthcare due to cost of doctors visits and prescriptions, confidentiality issues, and perceptions about their ability to communicate with health providers,5 general practice continues to be of importance to teenagers. This retrospective descriptive study describes patterns of prescribing for patients aged 13 to 19 years in New Zealand general practice over a 12-month period.

Methods

The Dunedin Royal New Zealand College of General Practitioners Research Unit (Dunedin RNZCGP Research Unit) collects anonymous health data voluntarily contributed by New Zealand general practitioners. Extraction programmes query data from practice management systems without including names, addresses and other identifying information. Each patient is allocated a unique code, which is individuating but non-identifiable. Data are imported into a database (Microsoft Access 2000) at the Dunedin RNZCGP Research Unit for further analysis.
The data collection period for this study was from 1 January 2000 to 31 December 2000. Practices were selected on the basis of their recording full electronic clinical records. Data relating to each consulting patient, including demographic details, health-card status, consultation records and prescribed medications, were included in the study data set. Age for each patient was calculated as at 1 January 2000 and patients aged 13 to 19 were identified.
Prescriptions were assigned codes from the Anatomical Therapeutic Chemical (ATC) classification system as used in the New Zealand Pharmaceutical Schedule. A therapeutic group is defined as a set of medicines that are used to treat the same or similar condition(s). The database includes information about some medications that do not receive Ministry of Health subsidies. Over-the-counter medications are included if they are prescribed by the general practitioner. Prescribed medication was calculated as a rate (number of prescriptions or medication items/consulting patient per annum) by age, sex, and community services card status. The proportion of consulting patients who received at least one medication item per annum and those who received five, ten, or twenty and more medication items were identified. The five most frequently prescribed therapeutic groups were identified, as were the five most frequently prescribed therapeutic subgroups.

Results

The database contains data extracted from 48 general practices (approximately 140 general practitioners) with a total consulting population of 225 348 patients of all ages (54.3% female) for the period 1 January 2000 to 31 December 2000. A Ministry of Health Survey indicates that this would represent approximately 80% of the estimated population base that is serviced by these practices (approximately 7.3% of New Zealand’s population as at 31 December 2000).6 Nineteen per cent of the patients were from the Central region, 25.2% from the Midland, 23.9% from the Northern, and 31.9% from the Southern region. During the study period these patients consulted 1 135 398 times (5.0 per consulting patient per annum), and were prescribed to 1 114 939 times (4.9 per consulting patient per annum). They were prescribed 668 742 repeat medication items (3.0 per consulting patient per annum), giving a total of 1 783 681 medication items (7.9 per consulting patient per annum). Females consulted more frequently than males (5.5 per consulting patient per annum versus 4.6).
From this larger data set, 20 216 patients aged 13 to 19 were selected (53.2% female). These patients consulted 64 365 times (3.2 per consulting patient per annum), and were prescribed to 47 758 times (2.4 per consulting patient per annum). They were prescribed 17 494 repeat medications (0.9 per consulting patient per annum) giving a total of 65 252 medication items (3.2 per consulting patient per annum). Females consulted more frequently than males (3.5 per consulting patient per annum versus 2.9). Table 1 shows that females were prescribed to more frequently than males (2.7 versus 2.0 scripts per annum and 3.7 versus 2.7 medication items per annum).

Table 1. Mean number of prescriptions and medication items per consulting patient per annum by age, sex and community services card (CSC) status

Age (years)
Females
Males
CSC
No CSC
All patients
Mean number of prescriptions
13
14
15
16
17
18
19
Total
2.2
2.3
2.6
2.9
3.1
2.8
2.6
2.7
2.0
2.2
2.2
2.0
2.0
1.9
1.8
2.0
2.5
2.7
2.8
3.2
3.4
3.1
2.7
2.9
1.9
2.0
2.2
2.2
2.1
1.8
1.9
2.0
2.1
2.2
2.4
2.5
2.6
2.4
2.3
2.4
Mean number of medication items
13
14
15
16
17
18
19
Total
2.9
3.1
3.5
4.2
4.3
4.0
3.6
3.7
2.6
3.0
3.0
2.7
2.7
2.6
2.4
2.7
3.3
3.7
3.8
4.4
4.7
4.5
3.7
4.0
2.4
2.7
3.0
3.1
3.0
2.4
2.5
2.7
2.8
3.0
3.2
3.5
3.6
3.4
3.1
3.2

Of all consulting patients aged 13 to 19, 70.2% were prescribed to at least once during the year, with 21.7% prescribed five or more medication items per annum, and only 1.9% prescribed 20 or more medication items during the study year (Figure 1).

Figure 1. Proportion of patients by frequency of prescribed items during the study period. Teenagers compared with the entire population.

CONTENT01.jpg

Of all patients aged 13 to 19, 38.0% were recorded as holding a CSC, with the rate of card holding increasing markedly at school-leaving age; 34.9% of 17-year-olds hold a card, increasing to 48.8% of 18-year-olds. Patients with a CSC were prescribed to more frequently than patients without a CSC (2.9 versus 2.0 scripts per annum), and were prescribed more medication items (4.0 versus 2.7 medication items per annum).

Table 2. The most frequently prescribed medication items. The proportion of therapeutic group by subgroup.

Therapeutic group (n)
Subgroups (% of therapeutic group)
Age (years)
13
14
15
16
17
18
19
All
Respiratory system (n)
Inhaled β-adrenoceptor agonists MDI
Inhaled corticosteroids MDI
Nasal preparations
Inhaled β-adrenoceptor agonists BA
Inhaled corticosteroids BA
All others
2525
23.6
18.3
18.3
13.3
10.2
16.3
2737
23.1
21.6
14.1
11.7
10.9
18.6
2647
26.0
18.1
17.9
11.5
11.7
14.8
2925
22.8
14.9
13.5
12.4
10.8
25.6
2526
28.5
21.9
16.6
10.3
7.2
15.5
2610
30.3
19.4
15.1
11.4
8.7
15.1
2190
27.7
23.3
14.9
9.5
7.1
17.5
18 160
25.9
19.5
15.7
11.5
9.6
17.8
Infections (n)
Antibacterials
Urinary tract infections
Antifungals
Antitrichomonal agents
Antivirals
All others
1872
96.3
0.6
1.3
0.5
1.1
0.2
2106
96.8
1.2
0.8
0.6
0.4
0.2
2204
95.2
1.0
1.4
1.3
0.8
0.3
2331
94.5
2.2
1.4
1.0
0.6
0.3
2681
91.7
3.4
2.0
1.7
1.2
0.0
2101
91.1
4.0
1.5
2.2
1.0
0.2
2037
90.9
3.6
1.4
2.7
1.2
0.2
15 332
93.7
2.3
1.4
1.4
0.9
0.3
Genito-urinary system (n)
Contraceptives hormonal
Anti-androgen oral contraceptives
Contraceptives hormonal, non-interchangeable
Contraceptives non-hormonal
Gynaecological anti-infectives
All others
79
24.1
5.1
11.4

20.3
17.7
21.4
206
36.4
9.7
21.8

16.0
9.2
6.9
622
45.2
16.9
18.0

12.4
5.6
1.9
1004
43.7
20.9
17.0

10.0
6.8
1.6
1483
52.8
20.8
12.4

6.7
6.3
1.0
1561
61.2
14.7
10.7

4.8
6.1
2.5
1729
57.3
19.1
10.6

5.7
6.1
1.2
6684
53.0
18.0
13.0

7.5
6.5
2.0
Dermatologicals (n)
Corticosteroids topical
Antibacterials topical
Anti-acne preparations
Emollients and barrier creams
Antifungals topical
All others
764
44.2
17.4
7.5
6.5
6.7
17.7
773
43.2
15.8
13.5
8.4
10.1
9.0
997
42.8
12.3
13.1
13.2
5.5
13.1
966
45.0
10.8
16.4
9.2
7.1
11.5
1109
46.5
10.2
11.4
12.0
6.7
13.2
1049
45.5
9.6
8.3
15.3
9.5
11.8
984
50.5
8.7
5.9
8.6
9.7
16.6
6642
45.5
11.8
10.9
10.7
7.9
13.2
Nervous system (n)
Analgesics
Antidepressants
Anti-epilepsy drugs
Antinausea and vertigo agents
Other CNS agents
All others
791
41.7
4.9
8.6
8.8
21.7
14.3
845
43.6
12.1
13.7
5.0
8.8
16.8
775
35.5
21.4
10.8
8.9
12.4
11.0
988
37.3
20.5
10.1
10.5
4.5
17.1
950
41.2
20.7
12.3
8.9
5.7
11.2
1172
27.2
28.2
20.0
8.4
2.0
14.2
953
32.8
30.7
10.2
11.4
1.9
13.0
6474
36.5
20.6
12.6
8.9
7.4
14.0
All other medications
1225
1478
1451
1843
2090
1834
2039
11 960
All medications
7256
8145
8696
10 057
10 839
10 327
9932
65 252
MDI = metered-dose inhaler; BA = breath-activated inhaler; CNS = central nervous system

Table 2 shows the most frequently prescribed medication items from the ATC groupings by therapeutic subgroup. Of all prescribed medications, 27.8% were from the respiratory system ATC grouping; 23.5% from infection; 10.2% from the genito-urinary system; 10.2% from dermatological; and 9.9% from the nervous system ATC grouping.

Discussion

There has been a paucity of published data on prescribing for teenagers in New Zealand general practice. This descriptive study examined the prescribing records of 48 New Zealand general practices for patients aged 13 to 19 years.
The results of this study indicate that teenagers who consult in general practice see their general practitioner less often than the study population as a whole (3.2 versus 5.0 contacts per annum) and are prescribed to less frequently (2.4 versus 4.9 prescriptions per annum).
Prescribing was a frequent outcome of a consultation, with 70.2% of patients prescribed at least one medication during the year. However, polypharmacy was not common, with only 8.1% of patients prescribed ten or more medication items over the year, compared with 21.3% of the entire study population.
Females consult and are prescribed to more frequently than males and this difference increases with age. Some of this difference can be explained by prescriptions for the genito-urinary system, primarily contraceptives. When this therapeutic group is removed from the analysis the mean number of medication items for females is 3.1 per consulting patient per annum, and males 2.7 per consulting patient per annum.
The most frequently prescribed therapeutic groups for patients aged 13 to 19 were for the respiratory system, infections, genito-urinary system, dermatologicals, and medications for the nervous system. These results mirror overseas data for this age group.7
Of concern is the relatively large proportion of teenagers prescribed anti-androgen oral contraceptives (presumably in part for their anti-acne properties). Evidence suggests a greater risk of fatal pulmonary embolism with combined oral contraceptives, and especially so for agents containing cyproterone acetate.8,9 More recent prescribing data are needed to ascertain if this level of prescribing is still occurring in light of recent media attention.
A greater number of medications are prescribed to teenagers with a community services card compared with those without. Higher levels of prescribing to card holders have previously been demonstrated for the population as a whole.10,11 Some of the highest levels of non-uptake of community services cards have been found amongst young people.12 If cost is a factor in general practice attendance for teenagers then non-uptake of cards needs to be addressed.
The most frequently prescribed therapeutic group for patients aged 13 to 19 is medication for the respiratory system, principally inhaled beta-adrenoceptor agonists and inhaled corticosteroids (Table 2). This is in accord with evidence of a high prevalence of respiratory-related illness amongst teenagers in New Zealand.13
The second most frequently prescribed therapeutic group is for infections, predominantly antibacterials, which make up 22.0% of all medication items prescribed to young people. Antibiotic resistance has been identified as an emerging threat for public health14 and there has been a call for an exploration of patient expectations in the consultation to help decrease prescribing rates.15 One consideration with the data presented is that some of these medications may be prescribed as needed and never dispensed.
Dermatological medications were the next most frequently prescribed therapeutic group, with topical corticosteroids making up 45.5% of all medications prescribed from this group. Other frequently prescribed medications include topical antibacterials and anti-acne preparations. Skin care is important for young people, with teenagers in particular quite stigmatised by skin problems such as acne, even in mild cases.16
Most medications prescribed from the nervous system ATC grouping are analgesics. However, the number of antidepressants prescribed increased with age. This is in accord with a reported increase of mental illness as young people move through adolescence.17 Closer examination of the data reveals that 72.4% of all antidepressants were selective serotonin reuptake inhibitors (SSRIs), which is in line with evidence that tricyclic antidepressants are less effective for teenagers than for adults.18 However, this may just be a reflection of a widespread increase in the prescribing of SSRIs in New Zealand.
The limitations of using the Dunedin RNZCGP database for research include potential bias in data collections (the magnitude and direction of this bias was the subject of a previous investigation, which found the database provided data that reflected similar morbidity and services to those of practices not contributing data to the network19); the lack of a defined population, as some patients consult with different practices or clinics over the study year; the cross-sectional study design; the fact that data recorded for prescribed medications do not take into account the difference between prescribed and dispensed medications; and that data are missing from non-prescribed, over-the-counter medications.
The study data set does not contain any data from family planning or sexual health clinics, which provide clinical services including sexual health checkups, contraception, pregnancy testing and counselling, and also run clinics in or near schools. There is some evidence that New Zealand teenagers would prefer to receive contraceptive services away from their general practice.20 The data presented are a reflection of general practice prescribing only, and reflect only one aspect of sexual health prescribing for young New Zealanders. However, the Dunedin RNZCGP database is a valuable tool in describing general practice prescribing for defined demographic groups without influencing or altering practice.
This study provides valuable baseline data of the medications prescribed for patients aged 13 to 19 years in an environment of very limited research either in New Zealand or the rest of the world. The most frequently prescribed medications for patients aged 13 to 19 were for treatment of the respiratory system, infections, the genito-urinary system, skin conditions, and the nervous system, and it is assumed this is a reflection of the morbidity of this population.
Author information: Jason Hall, Assistant Research Fellow; Isobel R Martin, Director, RNZCGP Research Unit, Department of General Practice, Dunedin School of Medicine, Dunedin
Acknowledgements: We thank the participating general practitioners, practice staff and research officers who managed the data collection. The RNZCGP Research Unit receives financial support from the New Zealand Health Information Service.
Correspondence: Jason Hall, Department of General Practice, Dunedin School of Medicine, University of Otago, P O Box 913, Dunedin. Fax: (03) 477 2056; email: jhall@gp.otago.ac.nz
References:
  1. Jacobson LD, Wilkinson CE. Review of teenage health: time for a new direction. Br J Gen Prac 1994;44:420–4.
  2. Walker ZA, Townsend J. The role of general practice in promoting teenage health: a review of the literature. Fam Pract 1999;16:164–72.
  3. Adolescent Health Research Group. A health profile of New Zealand youth who attend secondary school. NZ Med J 2003;116(1171). URL: http://www.nzma.org.nz/journal/116-1171/380/
  4. Ministry of Health. Youth health: a guide to action. Wellington: Ministry of Health; 2002.
  5. James R. The Well Teen Record©: a general practice tool to help address adolescent health care needs. NZ Fam Physician 1995;22:5–9.
  6. Ministry of Health. Taking the pulse – the 1996/97 New Zealand Health Survey. Wellington: Ministry of Health; 1999.
  7. Office of Population Censuses and Surveys. Morbidity statistics from general practice 1991–92. London: HMSO; 1995.
  8. Parkin L, Skegg DC, Wilson M, et al. Oral contraceptives and fatal pulmonary embolism. Lancet 2000;355:2133–4.
  9. World Health Organization Collaborative Study of Cardiovascular Disease and Steroid Hormone Contraception. Venous thromboembolic disease and combined oral contraceptives: results of international multicentre case-control study. Lancet 1995;346:1575–82.
  10. Sutton F, Crampton P. The community services card: does it make a difference to pharmaceutical utilisation? NZ Med J 2001;114:206–8.
  11. Gribben B. The community services card and utilisation of general practitioner services. NZ Med J 1996;109:103–5.
  12. Gribben B, Goodyear-Smith F. Can community service card possession be used to measure need? NZ Fam Physician 2002;29:24–9.
  13. Asher MI, Barry D, Clayton T, et al. The burden of symptoms of asthma, allergic rhinoconjunctivities and atopic eczema in children and adolescents in six New Zealand centres: ISAAC Phase One. NZ Med J 2001;114:114–20.
  14. Tenover FC, Hughes JM. The challenges of emerging infectious diseases. Development and spread of multiply-resistant bacterial pathogens. JAMA 1996;275:300–4.
  15. Arroll B, Goodyear-Smith F. General practitioner management of upper respiratory tract infections: when are antibiotics prescribed? NZ Med J 2000;113:493–6.
  16. Webster GF. Acne vulgaris. BMJ 2002;325:475–9.
  17. Ministry of Health. New Zealand Youth Health Status Report. Wellington: Ministry of Health; 2002.
  18. Hazell P, O’Connell D, Heathcote D, et al. Efficacy of tricyclic drugs in treating child and adolescent depression: a meta-analysis. BMJ 1995;310:897–901.
  19. Tilyard MW, Dovey SM, Spears GF. Biases in estimates from the RNZCGP computer research group. NZ Med J 1995;108:118–21.
  20. Morris E. Looking after yourself – some issues from 15 to 19 year olds on health and illness. Special report series 73. Wellington: Department of Health; 1984. p. 95–6.
     
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