Responsiveness

Command:

Statistics Agreement & responsiveness Responsiveness

Description

Allows to calculate several indices for responsiveness, which is the ability to detect any change.

Required input

• 1st and 2nd measurement: the variables for a 1st and 2nd measurement.
• Select: an optional selection criterion to include only a selected subgroup of subjects (rows).
• Options
  • Paired data: select this option when the variables for 1st and 2nd measurements contain paired data (measurements are repeated on the same subjects). If the 2 measurements are independent, unselect this option.

Results

Summary statistics

• The sample size, mean, variance and standard deviation of the 1st and 2nd measurement.

Difference

• The average difference between the two measurements with the pooled standard deviation and (in case of paired observations) the standard deviation of the paired differences.

Indices of responsiveness

• Effect size (ES) using baseline SD: this is the average difference divided by the standard deviation of the 1st measurement.
• Effect size (ES) using pooled SD: this is the average difference divided by the pooled standard deviation of both measurements.
• Standardized response mean (SRM): this is the average difference divided by the standard deviation of the differences between the paired measurements.

Literature

• Husted JA, Cook RJ, Farewell VT, Gladman DD (2000) Methods for assessing responsiveness: a critical review and recommendations. Journal of Clinical Epidemiology 53:459-168.
• Norman GR, Wyrwich KW, Patrick DL (2007) The mathematical relationship among different forms of responsiveness coefficients. Quality of Life Research 16:815-822.