Table 1

Model parameters, probability distributions and data sources for the decision-analytical model for economic evaluation of municipal ice cleat distribution programmes

ParameterAverage (range, if applicable)SEDistribution (probabilistic sensitivity analysis)Data source
Annual number of snow-related or ice-related fall injuries at baseline as a function of population size and climate (Embedded Image)21.6 (2.7, 472.6)Municipality-specific SE from regression predictionLognormalMunicipality-specific and age-specific data from National Patient Register21. Population data from Statistics Sweden30. Annual number of snow days from the Swedish Meteorological and Hydrological Institute*
Initial change in ice cleat use as a function of climate (Embedded Image)0.25 (0.09, 0.35)Municipality-specific SE from regression predictionLogit-normalNational survey (random sample, n=4608 aged 65+) conducted in 2007 by the Swedish Civil Contingencies Agency*
Compliance over time, multiplicative scaling factor (Embedded Image){Embedded ImageNot availableNoneCalibrated* simulation model to results from quasi-experimental evaluation in Gothenburg13
Effect of ice cleat use (RR), log scale−0.7990.333LognormalRandomised controlled trial12, RR=0.45 (95% CI: 0.23 to 0.85)†
Total programme cost per purchased ice cleat pair in 2018 Euros (c), log scale1.9980.100LognormalElectronic survey sent to all Swedish municipalities (n=34 responses with cost data)*
Benefit per averted injury in 2018 Euros329 783Not availableNoneSwedish Transport Administration17
  • *Additional information on data and estimation is provided in the online supplemental file.

  • †RR for falls (with or without an injurious outcome). Estimate for injurious falls was 0.1 (95% CI: 0.02 to 0.53) but was only based on a total of 11 events (one in the treatment group and 10 in the control group). Our preferred estimate (for falls) is supported by more data and is more conservative.

  • RR, relative risk.