Introduction 1 2 3 4 5 6 7 8 9 10 Materials and methods Inclusion of PTAMs 11 Levels for the quality of functioning of PTAMs 4 5 1 2 Table 1 Six domains for quality assessment of the PTAMs Parameters Number of FTO meetings Median duration of FTO meetings Joined preparation of GP and pharmacist (yes or no) Use of feedback information by prescription data concerning prescribed volume, costs/DDD and preferences in drug choice per GP (yes or no) Written down agreements on drug choices (yes or no) Routine check of adherence to the agreements made with prescription data (yes or no) Table 2 Four levels for the quality of functioning of PTAMs Level Description Level 1 No structured meetings Level 2 Frequent meetings without concrete decisions Level 3 Frequent meetings with concrete decisions, supported by use of feedback information with prescription data, but without evaluation of these decisions Level 4 Frequent meetings with concrete decisions and evaluation of these decisions Indicators for the quality of prescribing based on an adjusted DU90% method 3 11 7 7 Table 3 Selection of drugs from the seven groups, classification of guideline drugs and non-guideline drugs mostly encountered Group of drugs ATC  Guideline drugs Mostly encountered non-guideline drugs in our study population HMG CoA reductase inhibitors C10AA C10AA01, C10AA03 Simvastatin, Pravastatin Fluvastatin, Rosuvastatin, Atorvastatin a A02 A02A, A02BA Antacids, H2-receptor antagonists Proton pump inhibitors Antibacterials for systemic use J01 J01A, J01B Tetracyclines, Amfenicoles Quinolone antibacterials J01C except J01CR02 Beta-lactam antibacterials except amoxicilline and enzyme inhibitor Amoxiciline and enzyme inhibitor Cefalosporins J01E Sulfonamids and Trimethoprim J01F Macrolides, lincosamides, streptogramins J01X Other antibacterials (e.g. Fusidic acid) Antidepressants N06A N06AA09, N06AA02 Amitryptiline, Imipramine Maprotiline, Clomipramine, Fluoxetine N06AA10, N06AB08 Nortriptyline, Fluvoxamine Citalopram, Trazodone, Venlafaxine, Mirtazapin N06AB05, N06AB06 Paroxetine, Sertraline b N05BA N05CD07, N05CF02 Temazepam, Zolpidem Triazolam, Lormetazepam, Flunitrazepam, Loprazolam, Clobazam, Bromazepam, Lorazepam, Oxazepam, Chloordiazepoxide, Alprazolam, Zopiclone N05CD N05BA01 Diazepam N05CF Drugs for obstructive airway diseases R03 R03AC Selective beta-2-adrenoreceptor agonists Adrenergis for systemic use, Theophylline, Montelukast R03BA, R03BB Glucocorticoids, Anticholinergics R03BC01 Cromoglicic acid Oral blood glucose lowering drugs A10B A10BB Sulfonamides, urea derivatives Repaglinide, Thiazolidinediones A10BA02, A10BF01 Metformin, Acarbose a b 23 Prescribing according to ATC Prescribing according to guidelines Cost-effective prescribing Prescribing according to ATC 6 Prescribing according to guidelines 12 13 19 3 6 Cost-effective prescribing 6 Analyses Within all three indicator types, mean results (plus standard deviation) for the seven groups of drugs were calculated for each PTAM. With univariate and multivariate analyses of variance (MANOVA), variation between the levels of PTAMs was checked for all indicators of the seven drug groups within all three types of indicators. With MANOVA, analyses could be performed for all seven drug groups within one type of indicator simultaneously, adjusting for the fact that within a type of indicator, the same PTAMs were repeatedly measured for outcome of the seven drug classes. Further, we adjusted for the number of GPs per PTAM in categories from 1 to 10 GPs, 11 to 20 GPs, 21 to 30 GPs and more than 30 GPs per PTAM. All analyses were done with SPSS 12.1 for Windows (SPSS, Chicago, IL, USA). Results Participating PTAMs 4 Table 4 Numbers of PTAMs and GPs per level of PTAM Level of PTAMs Number of PTAMs (%) Number of GPs (SD) Not classified 7 (8) 6.6 (2.2) 1 21 (25) 10.4 (7.0) 2 23 (27) 8.1 (3.5) 3 15 (18) 9.3 (6.7) 4 18 (27) 10.9 (5.5) Total 84 (100)  Results of the three indicators Prescribing according to ATC 1 p p Prescribing according to guidelines 1 p p Cost-effective prescribing The cost per DDD within the DU90% segment on average ranged from 0.14 €/DDD for the benzodiazepine derivatives up to 0.99 €/DDD for the antibacterials for systemic use. In the remaining segment, the cost /DDD varied from 0.22 €/DDD for the benzodiazepine derivatives up to 1.62 €/DDD for the antibacterials for systemic use. The relationship between the cost/DDD of the rest segment and the cost/DDD of the DU90% segment was taken as indicator. A high result indicated a large difference in costs for the drugs seldom dispensed compared to those responsible for 90% of dispensed volume. Except for the group of the oral blood-glucose-lowering drugs (ratio 3.6), the groups had mean ratios between 0.9 and 1.8 for the costs/DDD in the remaining segment divided by the costs/DDD for the DU90% segment. p 1 p Fig. 1 Prescribing according to ATC, according to guidelines and cost-effective prescribing for different groups of drugs and all levels of PTAMs  Discussion 1 7 6 9 20 21 22 4 2 Another possible explanation could be selection bias caused by the voluntary participation in our study which was quite low. In 2004, there were in total 824 PTAMs in The Netherlands, of which, 14% were in level 1, 43% were in level 2, 20% were in level 3 and 23% were in the highest level 4. Due to our stratified invitation of 50 groups from each level and 57 groups of no classified level, we managed to include sufficient numbers within each level. On average, PTAMs in The Netherlands had 9.6 GPs, comparable to the number of participating PTAMs in our study. Only a quarter of the pharmacists corresponding with one third of the PTAMs invited finally succeeded in participation. Possibly, by this, we included primarily those PTAMs being well organised and with a high level of cooperation regardless of the quality level assessed. The classification into the different PTAM levels might not have created substantial differentiation between participating groups, and this could be an explanation for the fact that the results of our indicators were nearly the same for the different PTAM levels. A further limitation was our lack of information about the topics that have actually been discussed by the PTAMs in 2004 and earlier. It is possible that PTAMs made agreements on other aspects than the three indicator types chosen. Perhaps, agreements were made on the duration of treatment with antidepressants, on co-medication with HMGCoA inhibitors in patients with diabetes or on usage of new drugs, but as mentioned above, these were not measured by our three indicator types. In conclusion, it is difficult to define indicators based on the DU90% method that can readily distinguish differences in the quality of drug prescribing between PTAMs with different levels of functioning. Indicators have to be more sophisticated and to meet relevant aspects of the pharmacotherapy within certain drug classes. Items for classification of PTAM levels may need some reconsideration.