Impact of removal and restriction of me-too medicines in a hospital drug formulary on in- and outpatient drug prescriptions: interrupted time series design with comparison group.

BACKGROUND: The study covered in- and out-of-hospital care in a region in north-western Spain. The intervention evaluated took the form of a change in the hospital drugs formulary. Before the intervention, the formulary contained four of the five low molecular weight heparins (LMWHs) marketed in Spain. The intervention consisted of withdrawing two LMWHs (bemiparin and dalteparin) from the formulary and restricting the use of another (tinzaparin), leaving only enoxaparin as an unrestricted prescription LMWH. Accordingly, the aim of this study was to evaluate the effect on in- and outpatient drug prescriptions of removing and restricting the use of several LMWHs in a hospital drugs formulary. METHODS: We used a natural, before-after, quasi-experimental design with a control group and monthly data from January 2011 to December 2016. Based on data drawn from official Public Health Service sources, the following dependent variables were extracted: defined daily doses (DDD) per 1000 inhabitants per day (DDD/TID), DDD per 100 stays per day, and expenditure per DDD. RESULTS: The two compounds that were removed from the formulary registered an immediate decrease at both an intra- and out-of-hospital level (66.6% and 55.6% for bemiparin and 73.0% and 92.2% for dalteparin, respectively); similarly, the compound that was restricted also registered an immediate decrease (36.1% and 9.0% at the in- and outpatient levels, respectively); in contrast, the remaining LMWH (enoxaparin) registered an immediate, significant increase at both levels (44.9% and 32.6%, respectively). The intervention led to an immediate reduction of 6.8% and a change in trend in out-of-hospital cost/DDD; it also avoided an expenditure of €477,317.1 in the 21 months following the intervention. CONCLUSIONS: The results indicate that changes made in a hospital drugs formulary towards more efficient medications may lead to better use of pharmacotherapeutic resources in its health catchment area.

Tratamiento de la trombosis venosa profunda con heparinas de bajo peso molecular. Estudio comparativo con anticoagulación oral / Low-molecular-weight heparin without oral anticoagulants for the treatment of deep vein thrombosis

Antecedentes y métodos: Se dispone de datos limitados sobre la utilidad de la profilaxis secundaria de la trombosis venosa profunda (TVP) con heparinas de bajo peso molecular (HBPM). Comparamos dos cohortes de pacientes diagnosticados de TVP. Un grupo tratado con HBPM y otro grupo tratado con anticoagulantes orales. Se valoró la seguridad a la terminación del tratamiento anticoagulante, al año y para la incidencia de fracturas a los 2,5 años. La seguridad se evaluó por la tasa de hemorragias mayores y de fracturas y la eficacia por la tasa de recidiva trombótica precoz (durante el tratamiento anticoagulante) y al año. Resultados: de 65 pacientes tratados con HBPM, presentaron una tasa de hemorragia mayor de 1,5% (IC95% 0,08-9,40) y de fractura de7,7% (IC95% 2,87-17,75), presentaron recidiva temprana 1,5% (IC 95% 0,08-9,40) y recidiva al año 3% (IC95% 0,53-11,64). De 118 pacientes tratados con anticoagulantes orales presentaron una tasa de hemorragia mayor de 3,4% (IC95% 1,09 a 8,97), odds ratio 0,33, una tasa de fractura de 11% (IC95% 16,23 a 18,44), odds ratio 0,66, recidiva temprana de 5% (IC95% 2,08 a 11,20), odds ratio 0,60 y recidiva al año de 3,4% (IC95% 1,09 a 8,97), odds ratio 0,33. Conclusiones: La profilaxis secundaria de la trombosis venosa profunda con HBPM es al menos tan eficaz y segura como el tratamiento con anticoagulantes orales. El tratamiento con HBPM no ha causado incremento de las fracturas

Background and methods: The available data on the utility of low molecular-weight heparins (LMWH) in the secondary prophylaxis of deep vein thrombosis (DVT) are limited. We compared two cohorts of patients diagnosed of DVT. One group followed treatment with LMWH and the other group did with oral anticoagulants (acenocoumarol). Safety was evaluated by the rate of major hemorrhage and 2.5-years period fracture rate, and efficacy was evaluated as the rate of early recurrence and one-year recurrence rate. Results: Of 65 patients treated with LMWH, the hemorrhagic rate was 1.5% (95% CI 0.08-9.40), fracture rate was 7.7% (95% CI 2.87-17.75), early recurrence was 1.5% (95% CI 0.08-9.40) and one-year recurrence was 3% (95% CI 53-11.64). In 118 patients treated with oral anticoagulants the hemorrhagic rate was 3.4% (95% CI 1.09-8.97), odds ratio 0.33, the fracture rate was11% (95% CI 16.23-18.44), odds ratio 0.66, the early recurrence ratewas 5% (95% CI 2.08-11.20), odds ratio 0.60 and one-year recurrence was 3.4% (95%CI 1.09-8.97), odds ratio 0.33. Conclusions: Secondary prophylaxis of DVT with LMWH is as safeand effective as classical treatment with oral anticoagulants. In this study the 2.5-year period fracture rate was similar in both groups of treatment