The shorter version with 40 items (SGRQ-C) was validated specifically for COPD. The intention with this revision was to improve the signal to noise of the calculated scores by removing items that had weaker instrument properties, and at the same time produce scores equivalent to the SGRQ without specifying a recall period. The scoring algorithm for the SGRQ and SGRQ-C has been described in detail. A global score, and scores for each component (ie, symptoms, activity, and impacts) is calculated. Each component score is derived by dividing the summed weights, unique for all questions, by the maximum possible weight. To calculate the SGRQ and SGRQ-C score by hand may not be feasible in a routine setting because of its size and complexity. Even the researcher may find it cumbersome. Shorter instruments for measuring respiratory morbidity are available, but these may perform less well than their longer counterparts.