Table 1 Study parameters for alternative study scenarios simulated with the cost model

Design 1: current study

4^b/2^{a, c}

2^b/1^c

80

4

0.30

1

Design 2: no training or software costs

0

0

80

4

0.30

1

Design 3: double the work shift files

4^b/2^{a, c}

2^b/1^c

160

4

0.30

1

Design 4: full observation overlap

4^b/2^{a, c}

2^b/1^c

80

4

1.0

1

Design 5: 2 hours observed per half-shift

4^b/2^{a, c}

2^b/1^c

80

4

0.125

1

Design 6: longer observer analysis time^b

4 ^b

2 ^b

80

4

0.30

2

Design 7: shorter analysis time for inclinometer recordings and questionnaires

1 ^a /2 ^c

0 ^a /1 ^c

80

4

0.30

0.5