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BMC Family Practice

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Trends in influenza vaccination uptake among people aged over 74 years, 1997–2000: Survey of 73 general practices in Britain

  • Elizabeth Breeze1Email author,
  • Punam Mangtani2,
  • Astrid E Fletcher1,
  • Gill M Price1,
  • Sari Kovats3 and
  • Jenny Roberts3
BMC Family Practice20045:8

https://doi.org/10.1186/1471-2296-5-8

Received: 23 October 2003

Accepted: 20 April 2004

Published: 20 April 2004

Abstract

Background

Influenza vaccination policy for elderly people in Britain has changed twice since 1997 to increase protection against influenza but there is no information available on how this has affected vaccine uptake, and socioeconomic variation therein, among people aged over 74 years.

Methods

Vaccination information for 1997–2000 was collected directly from general practices taking part in a MRC-funded Trial of the Assessment and Management of Older People in the Community. This was linked to information collected during assessments carried out as part of the Trial. Regression modelling was used to assess relative probabilities (as relative risks, RR) of having vaccination according to year, gender, age, area and individual socioeconomic characteristics.

Results

Out of 106 potential practices, 73 provided sufficient information to be included in the analysis. Uptake was 48% (95% CI 45%, 55%) in 1997 and did not increase substantially until 2000 when the uptake was a third higher at 63% (50%, 66%). Vaccination uptake was lower among women than men (RR 0.9), people aged 85 or more compared to people aged under 80 (RR 0.9), those in the most deprived areas (RR 0.8) compared to the least deprived, and was relatively high for those in owner-occupied homes with central heating compared to other non-supported housing (RR for remainder = 0.9). This pattern did not change over the years studied.

Conclusions

Increased uptake in 2000 may have resulted from the additional financial resources given to practices; it was not at the expense of more disadvantaged socioeconomic groups but nor did they benefit disproportionately.

Background

Influenza can have a dramatic impact on morbidity and mortality. Routine influenza vaccination is protective against illness [1], acute respiratory hospitalisations and deaths [2]. The Department of Health recommended routine administration of the influenza vaccine to all aged over 74 years in 1998 and in 2000 extended this to all aged over 64 years while adding an item-of-service payment [3]. The GPs were allocated extra funds for the purposes of identifying and communicating individually with those eligible, monitoring progress of the vaccination campaign, and helping practices with insufficient staff. Financial incentives for interventions have been proposed as a factor for successfully translating other evidence into practice [4] and trials randomising US primary care physicians confirm this for influenza vaccination. In the US healthcare setting an offer of up to $1.60 per vaccine produced a 7% increase in immunisation rates in patients aged over 64 years [5, 6] and in the UK target performance-related bonuses have been effective for other preventive practice [4].

In 2000 65% of over-64 year olds in Britain were vaccinated against influenza [7]. We are not aware of any prospective studies specifically designed to evaluate how change in policy was changing the patterns of uptake by socioeconomic factors in Britain. This is of interest in the light of the Government Policy to tackle health inequalities [8]. The MRC Trial of Assessment and Management of Older People in the Community (MRC Study) provided the opportunity to evaluate these changes in vaccination policy retrospectively in terms of overall uptake and variation by socioeconomic status in the more vulnerable over-74 year olds during the period 1997–2000.

Methods

Assessments for the MRC Study, described elsewhere [9], took place between 1995 and 1999 in 106 general practices that belonged to the General Practice Research Framework. They were spread throughout Great Britain and the selection was stratified by practice-level tertiles of Jarman score and Standardised Mortality Ratio. For any one practice the assessments were spread over one year but the practices were recruited in phases during this period. In May 2000 these practices were asked to provide data on individuals' vaccination status in each year from the year they joined the Study to 1999. They were approached again in 2001 to provide data for the winter 2000 season. They were asked to use their own records for the data.

Seventy-three practices provided useable data on vaccinations: 55 supplied data for each of 1997–2000 winter seasons (September-February), 11 for 1997–1999, and seven for 2000 only. Their characteristics are given in Table 1: 28 practices provided the data direct from their electronic records and 44 practices extracted the data manually from their records (one not known). Eleven other practices were excluded because not able to provide information on past vaccination status for people who had since died.
Table 1

Characteristics of practices by years took part in the vaccination study

 

Years provided vaccination records used in analyses

 

1997–1999

2000

1997–2000

None

Jarman tertile

    

Low

3

3

16

13

Med

7

2

16

8

High

1

2

23

12

SMR tertile

    

Low

2

2

18

10

Med

3

2

19

11

High

6

3

18

12

List size

    

<5000

3

0

20

10

5000 or more

8

7

35

23

Number of GPs

    

<7

10

6

51

31

7 or more

1

1

4

2

 

11

7

55

33

Postcode linkage gave the area Carstairs deprivation score [10] and population density for the Enumeration District of patient's residence. One of the trial interventions compared giving a detailed as well as a brief assessment to everyone (universal arm) with giving a detailed assessment only to those whose brief assessments fulfilled pre-specified criteria of need for further investigation (targeted arm).

The Trial included people aged over 74 years in the year the practice undertook the trial intervention; it excluded people in long-term nursing care or with terminal illness. Additional inclusion criteria for the vaccination analysis in any year were being alive on 30 November and still registered with the Trial practice.

Analysis strategy

The analyses are confined to those for whom vaccination records were available in the practices that provided information. Trends were confined to 1997–2000 since relatively few practices were participating before this time. Generalised estimating equations based on Poisson regression with robust standard errors were used – this is an alternative to logistic regression and enables direct estimation of risk ratios. Modelling took into account clustering within practice and person by adjusting for intra-cluster correlations in using robust standard errors at the practice level. The software package Stata 7 was used [11].

First, analyses of uptake by year were carried out only adjusting for age and gender, using information from all 73 practices (Model 1). Then these were adjusted for the deprivation and urbanisation levels of enumeration districts in which people lived (Model 2). Analyses with both individual and area level socio-economic factors were confined to the 42 practices in the universal arm where all subjects had detailed assessments. Before adding in these socioeconomic factors (Models 4 and 5) the analysis by year adjusted for gender and age was repeated on the universal arm subset (Model 3) so that any differences in trends in this subset compared to the full sample could be seen. To assess whether variation by socioeconomic factors had changed over time, Wald tests were carried out for statistical significance of interactions between year and each of the socioeconomic and urbanisation measures in turn.

The analyses presented took advantage of the larger sample size from including everyone in the relevant practices with a vaccination record. To exclude the possibility that the yearly uptake figures might be distorted by changes in practices and people included in the figures, analyses were also run on the subgroup who had records for all four years.

Results

There were 42057 people eligible for the trial in all 106 practices, 28492 in the 72 practices participating, of whom 24654 (87%) people had vaccination records for at least one year. This may underestimate success rate in obtaining information since some of those who were eligible for the trial may no longer have been in the practice for the vaccine follow-up period; information was not sufficiently complete for non-responders to the Trial to calculate the exact numbers left in the practice. Postcode linkage was missing for 3079 (12%) leaving 21575 for analysis; 51% of these, (10951) had information for all years (the 4-year subsample). The characteristics of the sample in each year are given in Tables 2 (73-practice sample) and 3 (42-practice sample). The sample in successive years aged as expected. Composition by gender, Carstairs deprivation index and urban indicator changed little in successive years. The only consistent difference between the 73-practice and 42-practice samples, other than size, were a smaller percentage living in the most deprived areas in the latter. The people that were in the sample for all four years were younger than the total sample available in 1997. The gender age composition of the two subsamples in 1997 was also very similar to that of the 42057 people eligible for the trial (not shown).
Table 2

Characteristics of sample for whom vaccination data available, by year: all practices

 

1997 n = 18162 63 practices1

1998 n = 17962 66 practices2

1999 n = 16254 66 practices

2000 n = 13762 62 practices3

In all years n = 10951 53 practices Age in 1997

 

No

%

No

%

No

%

No

%

No

%

Male

6457

35.6

6339

35.3

5687

35.0

4797

34.8

3778

34.5

< 80 yrs

2773

15.3

2376

13.2

1612

9.9

672

5.1

1873

17.1

80–84 yrs

2231

12.3

2349

13.1

2377

14.6

2535

18.0

1298

11.9

>= 85 yrs

1453

8.0

1614

9.0

1698

10.4

1588

11.5

607

5.5

Median age

 

(80)

 

(81)

 

(82)

 

(82)

 

(80)

Female

14551

64.4

11623

64.7

10567

65.0

8967

65.2

7173

65.5

<80 yrs

4139

22.8

3503

19.5

2387

14.7

1015

7.4

2954

27.0

80–84 yrs

4041

22.2

4156

23.1

4089

25.2

4106

29.8

2517

23.0

>=85 yrs

3525

19.4

3964

22.1

4091

25.2

3846

28.0

1702

15.5

Median age

 

(82)

 

(82)

 

(83)

 

(84)

 

(81)

Deprivation quintile 4

          

Least deprived

4567

25.2

4689

26.1

4287

26.4

3419

24.8

2587

23.6

2nd quintile

5479

30.2

5420

30.2

4933

30.4

3963

28.8

3290

30.0

3rd quintile

3822

21.0

3694

20.6

3336

20.5

3037

22.1

2399

21.9

4th quintile

2444

13.5

2432

13.5

2182

13.4

2000

14.5

1518

13.9

Most deprived

1850

10.2

1727

9.6

1516

9.3

1343

9.8

1157

10.6

Population density 5

          

<250 pers km-2

6156

33.9

6116

34.0

5539

34.1

4509

32.8

3931

35.9

250–1000 pers km-2

4472

24.6

4336

24.1

3913

24.1

3652

26.5

2691

24.5

1000–2500 pers km-2

5074

27.9

4966

27.6

4511

27.8

3549

25.8

2602

23.8

>=2500 pers km-2

2460

13.5

2544

14.2

2291

14.1

2052

14.9

1727

15.8

1. 53 practices in all years plus 10 practices in years 1997–1999 2. 53 practices in all years plus 11 practices in years 1997–1999 plus 2 practices in 1998–2000 3. 53 practices in all years plus 7 practices in 2000 only plus 2 practices in 1998–2000 4. Quintiles defined according to distribution of Enumeration Districts in Britain 5. Population density smoothed over a 5-kilometre radius from the centroid of the Enumeration District

Table 3

Characteristics of sample for whom vaccination data available, by year: practices with individual socioeconomic information

 

1997 n = 8334 37 practices1

1998 n = 7944 38 practices2

1999 n = 7294 38 practices

2000 n = 6159 34 practices3

In all years n = 5130 29 practices

 

No

%

No

%

No

%

No

%

No

%

Male

3170

38.0

3026

38.1

2753

37.7

5498

34.7

1938

37.8

< 80 yrs

1378

16.5

1116

14.0

735

10.0

815

5.1

948

18.5

80–84 yrs

1105

13.3

1135

14.3

1184

16.2

2857

18.0

677

13.2

>= 85 yrs

687

8.2

775

9.8

834

11.4

5498

11.5

313

6.1

Median age

 

(80)

 

(81)

 

(82)

 

(82)

 

(80)

Female

5164

62.0

4918

61.9

4541

62.3

1035

65.3

3192

62.2

<80 yrs

1873

22.5

1509

19.0

1030

14.2

6

7.9

1354

26.4

80–84 yrs

1775

21.3

1760

22.2

1794

24.6

1259

29.7

1109

21.6

>=85 yrs

1516

18.2

1649

20.8

1717

23.5

4711

27.7

729

14.2

Median age

 

(81)

 

(82)

 

(83)

 

(83)

 

(81)

Deprivation quintile 4

          

Least deprived

2247

27.0

2206

27.8

2060

28.2

1811

29.4

1429

27.9

2nd quintile

2412

28.9

2269

28.6

2076

28.5

1768

28.7

1468

28.6

3rd quintile

1831

22.0

1767

22.2

1620

22.2

1380

22.4

1155

22.5

4th quintile

1203

14.4

1128

14.2

1025

14.1

790

12.8

708

13.8

Most deprived

641

7.7

574

7.2

513

7.0

410

6.7

370

7.2

Population density 5

          

<250 pers km-2

2578

30.9

2363

29.8

2164

29.7

1944

31.6

1778

34.7

250–1000 pers km-2

2168

26.0

2071

26.1

1905

26.1

1610

26.1

1240

24.2

1000–2500 pers km-2

2382

28.6

2250

28.3

2085

28.6

1591

25.8

1259

24.5

>=2500 pers km-2

1206

14.5

1260

15.9

1140

15.6

1014

16.5

853

16.6

Socioeconomic status 6

          

Owner & c heating

4896

58.8

4737

59.6

4440

60.9

3893

63.2

3225

62.9

   without c heating

784

9.4

738

9.3

675

9.2

575

9.3

484

9.4

Renter & c heating

1648

19.8

1557

19.6

1378

18.9

1104

17.9

908

17.7

   without c heating

356

4.3

322

4.1

287

3.9

197

3.2

181

3.5

Supported housing

650

7.8

590

7.4

514

7.1

390

6.3

332

6.5

1. 29 practices in all years plus 8 practices in years 1997–1999 2. 29 practices in all years plus 8 practices in years 1997–1999 plus 1 practice in 1998–2000 3. 29 practices in all years plus 4 practices in 2000 only plus 1 practice in 1998–2000 4. Quintiles defined according to distribution of Enumeration Districts in Britain 5. Population density smoothed over a 5-kilometre radius from the centroid of the Enumeration District 6. C heating = central heating. Supported accommodation includes sheltered housing and residential homes

In successive years 1997 to 2000 48% (95% CI 45–55%), 50% (47–54%), 51% (49–55%) and 63% (60–66%) were vaccinated. The pattern was replicated among gender-age sub-groups and among the 4-year subsample. Adjusted for gender and age the proportional increase in vaccination uptake in 2000 compared to 1997 was 32% (95% CI 25–41%) and small but statistically significant in interim years (Table 4 Model 1). The 4-year subsample produced very similar results (not shown). Additionally in this subsample, whereas only 10% of those unvaccinated in 1997–8 were vaccinated in 1999, 28% of those unvaccinated in 1997–9 were vaccinated in 2000.
Table 4

Modelling effect of year and socioeconomic factors on vaccination uptake: risk ratios (95% confidence intervals)

Categories

Model 11 73 practices n = 66140 records3

Model 21 73 practices n = 66140 records3

Model 31 42 practices2 n = 29731 records3

Model 41 42 practices2 n = 29731 records3

Model 51 42 practices2 n = 29731 records3

Year

     

1997

1.00

1.00

1.00

1.00

1.00

1998

1.06 (1.02,1.09)

1.05 (1.02,1.09)

1.08 (1.03,1.13)

1.07 (1.03,1.12)

1.08 (1.03,1.13)

1999

1.09 (1.05,1.14)

1.09 (1.05,1.14)

1.10 (1.04,1.16)

1.09 (1.03,1.16)

1.09 (1.04,1.15)

2000

1.33 (1.25,1.42)

1.33 (1.25,1.42)

1.32 (1.22,1.43)

1.32 (1.22,1.42)

1.32 (1.22,1.42)

 

p < 0.001

p < 0.001

p < 0.001

p < 0.001

p < 0.001

Gender

     

Male

1.00

1.00

1.00

1.00

1.00

Female

0.89 (0.87,0.91)

0.89 (0.87,0.91)

0.89 (0.87,0.92)

0.88 (0.86,0.91)

0.90 (0.87,0.92)

 

p < 0.001

p < 0.001

p < 0.001

p < 0.001

p < 0.001

Current age (years)

    

Under 80

1.00

1.00

1.00

1.00

1.00

80–84

1.01 (0.98,1.04)

1.01 (0.98,1.04)

1.01 (0.97,1.05)

1.02 (0.98,1.07)

1.02 (0.98,1.06)

85 or more

0.92 (0.88,0.96)

0.92 (0.88,0.96)

0.89 (0.83,0.94)

0.91 (0.85,0.96)

0.89 (0.84,0.94)

 

p < 0.001

p < 0.001

p < 0.001

p < 0.001

p < 0.001

Carstairs quintiles (deprivation)

   

Least

Not in model

1.00

Not in model

1.00

1.00

Second

 

1.00 (0.95,1.05)

 

1.04 (0.97,1.12)

1.05 (0.97,1.13)

Mid

 

0.98 (0.92,1.05)

 

1.01 (0.93,1.10)

1.03 (0.94,1.13)

Fourth

 

0.95 (0.84,1.08)

 

0.98 (0.84,1.16)

0.99 (0.83,1.18)

Most

 

0.82 (0.73,0.93)

 

0.82 (0.72,0.94)

0.85 (0.70,1.05)

  

p = 0.011

 

p =< 0.001

p = 0.10

Population density category (people per sq km)

   

-250

Not in model

1.00

Not in model

1.00

1.00

-1000

 

0.91 (0.80,1.03)

 

0.99 (0.84,1.16)

0.99 (0.83,1.17)

-2500

 

0.99 (0.88,1.11)

 

1.08 (0.93,1.26)

1.10 (0.94,1.30)

>2500

 

1.04 (0.91,1.19)

 

1.13 (0.96,1.32)

1.14 (0.95,1.36)

  

p = 0.30

 

p = 0.36

p = 0.27

Individual socioeconomic position 4

   
 

Not in model

Not in model

Not in model

Not in model

 

A

    

1.00

B

    

0.94 (0.89,0.98)

C

    

1.03 (0.96,1.11)

     

p = 0.018

1. P-values for contribution of whole factor to the model; modified Wald test. Generalised estimating equations based on Poisson regression with robust standard errors calculated at the practice level. Models all factors shown. 2. Individual socioeconomic information was only available in a subset of the practices because of the nature of the interventions 3. There was one record per person per year of eligibility for inclusion in the vaccination analysis 4. A = owner occupier with central heating. B = three categories combined because very similar in uptake: owner-occupier without central heating, renter with central heating, renter without central heating; C = supported housing

Coverage was lower among women and people aged 85 years or over (Model 1) and for those in the most deprived quintile of Carstairs (Model 2). In the subset with information on individual socioeconomic position uptake was similar among people in owner-occupied accommodation with central heating and those in sheltered or residential homes, but 6% lower among others (Model 4). The difference in uptake by area deprivation was statistically significant in this subset before adjustment for individual socioeconomic position (Model 4), but not afterwards (Model 5). Part of the shortfall in uptake in the most deprived areas was accounted for by the individual position. Although variation by population density was not statistically significant there is some indication of higher uptake in urban areas in this group of practices. There were no significant interactions between year and any of area deprivation, population density, individual socioeconomic position, or gender.

Discussion

Compared with 1997, vaccination uptake increased noticeably in 2000, coinciding with greater emphasis on meeting targets, but not in 1998 when policy changed to routine vaccination for everyone aged over 74 years. As our sample only covers those aged 75 years and over, it is assumed that the financial incentives and resources applied to practices played a greater part in the upturn than the extension of the policy to all aged 65 years and over. In 2000 the target of 60% coverage in over-64 year olds was exceeded in our sample of over-74 year olds. The modest socioeconomic differentials in influenza vaccine uptake were also unchanged over time (no significant interactions), i.e. the increased uptake was not at the expense of the less well-off groups but nor did it benefit them disproportionately. It appears that the extra effort in 2000 did not target by socioeconomic or gender or age-group (e.g. over 80s compared to under 80s). The effort may have been in terms of increasing attention to those not considered of the highest risk. Possibly indicative of this, the relative risk for being vaccinated for people reporting a respiratory problem at assessment compared with those who did not was 1.15 (95% CI 1.09–1.22) in 1997 and 1.06 (95% CI 1.03–1.09) in 2000. Equivalent figures for a CVD history were 1.10 (1.05, 1.15) in 1997 and 1.04 (1.00, 1.07) in 2000. However, this evidence should be treated cautiously since we only have health status at the time of assessment so that by 2000 it may have been out of date. Improved recording might account for some of the observed increase in 2000.

The study has limitations. To increase the size of the study, the analysis presented included everyone in the practices with records in a given year; this means that the year-on-year figures reflect not only real change in uptake for individuals but also any substantial change in composition of the samples from year to year. It is therefore reassuring both that sample composition was similar from year to year (Tables 2, 3) and that confining results to those with information for all four years produced similar results. We did not consider it sufficient to use the subsample with records for all four years, in case they were a select group whose survival in the practice was the result of better health, and a greater tendency to take prophylactic action. However, their uptake of vaccination in 1997 was no higher than the fuller sample in 1997. A separate paper evaluating a wider range of factors at practice and individual level associated with uptake in 2000 is in preparation.

The socioeconomic information refers to that pertaining at the time of assessment. There may be misclassification in later years, if people have moved into sheltered or institutional accommodation where vaccination is encouraged. However, if this was distorting the results, one would expect the tenure differential to be weaker the more time had elapsed since assessment but this was not found.

Conclusions

Substantial scope for improvement remains but the upturn in 2000 should encourage efforts to increase vaccine uptake further. Socioeconomic variation was less substantial than the authors expected but, in keeping with government policy, we recommend periodic assessment of, and response to, socio-economic differentials in access to this preventive health care intervention [12].

Declarations

Acknowledgements

The authors would also like to thank the MRC Trial investigators and Trial Steering Committee of the MRC Trial for allowing them to use the Trial data. The investigators, other than Professor Astrid Fletcher, were Professor Chris Bulpitt (Imperial College London), Dr Dee Jones (University of Wales) and Dr Alistair Tulloch (University of Oxford). The Medical Research Council (MRC), Department of Health and Scottish Office funded the main trial (grant no G9223939). The collection of vaccination data was funded as part of an MRC project grant for an add-on study of winter mortality (grant no G99000506); the analyses in this paper were funded by the Department of Health Inequalities in Health Research Initiative (grant no 121/7415).

Authors’ Affiliations

(1)
Department of Epidemiology and Population Health, London School of Hygiene and Tropical Medicine
(2)
Department of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine
(3)
Department of Public Health and Policy, London School of Hygiene and Tropical Medicine

References

  1. Govaert TM, Thijs CT, Masurel N, Sprenger MJ, Dinant GJ, Knottnerus JA: The efficacy of influenza vaccination in elderly individuals. A randomized double-blind placebo-controlled trial. J Am Med Ass. 1994, 272: 1661-1665. 10.1001/jama.272.21.1661.View ArticleGoogle Scholar
  2. Mangtani P, Cumberland P, Hodgson C, Roberts J, Cutts F, Hall AJ: Effectiveness of influenza vaccine against respiratory hospitalisations and deaths among people aged over 64 years: a cohort study using the United Kingdom General Practice Research Database. J Inf Dis. 2004Google Scholar
  3. Officer Chief Medical: Influenza immunisations. 1st August 2000. 2000, PL/CMO/2000/3:Google Scholar
  4. Kouides RW, Lewis B, Bennett NM, Bell KM, Barker WH, Black ER, Cappuccio JD, Raubertas RF, LaForce FM: A performance-based incentive program for influenza immunization in the elderly. Am J Prev Med. 1993, 9: 250-255.PubMedGoogle Scholar
  5. Kouides RW, Bennett NM, Lewis B, Cappuccio JD, Barker WH, LaForce FM: Performance-based physician reimbursement and influenza immunization rates in the elderly. The Primary-Care Physicians of Monroe County. Am J Prev Med. 1998, 14: 89-95. 10.1016/S0749-3797(97)00028-7.View ArticlePubMedGoogle Scholar
  6. McDaid D, Maynard A: Translating evidence into practice. The case of influenza vaccination. Eur J Public Health. 2001, 11: 453-455.View ArticlePubMedGoogle Scholar
  7. Joseph C, Goddard N: Influenza vaccine uptake in the elderly: results from a rapid assessment of the effectiveness of new government policy in England for the winters 2000/2001 and 2001/2002. Vaccine. 2003, 21: 1137-1148. 10.1016/S0264-410X(02)00505-4.View ArticlePubMedGoogle Scholar
  8. Treasury HM, Health Department of: Tackling health inequalities. Summary of 2002 cross-cutting review. 2002, London, Department of Health Publications, 29854: 1-28.Google Scholar
  9. Fletcher A, Jones D, Bulpitt C, Tulloch A: The MRC trial of assessment and management of older people in the community: objectives, design and interventions [ISRCTN23494848]. BMC Health Serv Res. 2002, 2: 21-10.1186/1472-6963-2-21.View ArticlePubMedPubMed CentralGoogle Scholar
  10. Carstairs V, Morris R: Deprivation: explaining differences in mortality between Scotland and England and Wales. B M J. 1989, 299: 886-889.View ArticleGoogle Scholar
  11. Statacorp: Stata statistical software release 7.0. 2002, College Station, Texas, Stata PressGoogle Scholar
  12. Macintyre S: Evidence based policy making. Br Med J (Clin Res Ed). 2003, 326: 5-6. 10.1136/bmj.326.7379.5.View ArticleGoogle Scholar
  13. Pre-publication history

    1. The pre-publication history for this paper can be accessed here:http://www.biomedcentral.com/1471-2296/5/8/prepub

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© Breeze et al; licensee BioMed Central Ltd. 2004

This article is published under license to BioMed Central Ltd. This is an Open Access article: verbatim copying and redistribution of this article are permitted in all media for any purpose, provided this notice is preserved along with the article's original URL.

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