FV-78 | The consequences of drug shortages on cost and quality on physician treatment behavior

Prof. S. Felder, Prof. K. Blankart, C. Plaza 

Health Economics

Research Objectives
The objective of this project is to analyze the consequences of drug shortages on physician treatment behavior with regards to cost and quality of prescribing in Switzerland. We will employ the potential outcomes framework and empirically compare prescribing behavior in drugs facing a drug shortage to prescribing in absence of a shortage. Our goal is to describe the scope of drug shortages and to identify causal effects of drug shortages on cost and quality of prescribing on physician practice and drug level using event study and difference-in-difference analysis.


Completed steps
We curated data from multiple sources to 1) identify the scope of reported drug shortages in Switzerland in the universe of drugs at national level, 2) analyze consequences on direct cost, and 3) analyze consequences on cost and quality of prescribing at physician practice level. These sources are a national database on drug shortages (drugshortage.ch), the pharmaceutical reference database (Spezialitätenliste), nation-wide prescription data from Swiss physician practices (provided by SASIS AG) and drug volume data (provided by the health insurer Helsana AG). To analyze the consequences of drug shortages at physician level, based on the curated data, we have identified four case vignettes to define treatment and control groups and the timing of the shortage, i.e., Angiotesin II receptor Blockers and ACE inhibitors in antihypertensive medication, triptans for migraine treatment and medications to treat epilepsy. 

Shortages have been classified by their occurrence, duration, intensity and cost to describe the scope of the phenomenon in the universe of drugs. We currently finalize analyses that will indicate the changes in average cost of the medications prescribed when shortages are present for the year 2018. Physician level data has been analyzed descriptively. Further, we have specified the elements of the planned difference-in-differences (DiD), event study, and regression discontinuity in time (RDiT) methodologies. All econometric analyses which will be performed in the course of January to March 2021.


Results
Between 2015 and June 2020, shortages occur in about 50% of the 3967 drug markets analyzed, of which in 777 markets, all options of the same market were reported on shortage of more than 2 weeks (Table 1). When all options are short, these shortages last for 14.49 months, on average. Furthermore, we find that among 8514 physicians who billed Valsartan, there was an 8% decrease in the total number of prescriptions and a 5% decrease in the costs of prescriptions 3 months after the shortage (in comparison to the 3 months before the structural break is identified). The figures reveal that drug shortages are a most relevant issue.

 

Publications 
Two manuscripts are in the process:

“Drug shortages in Switzerland 2015-2020: drug expenditures in outpatient care”, Katharina Blankart and Stefan Felder. This will be a descriptive analysis of drug shortages in Switzerland with a focus on the consequences on direct costs of medication in times of a shortage. In progress and planned for June 2021. 

“The consequences of drug shortages on cost and quality on physician treatment behavior”, Katharina Blankart, Stefan Felder, Camila Plaza de Laifer. In progress and planned for June 2021.
Final report, June 2021


Conferences, Presentations

Conference applications for 2021:
EUHEA PhD student-supervisor workshop – September 2021
Lola HESG – May 2021