64 CHAPTER 2.2 This calculation method is in accordance with the approach provided by AGREE II Instrument. The scores of appraisers 1 and 2 were both replaced by the consensus score when a third appraiser was consulted. After scoring the elements, clarity ratings were categorized into low (<33.3%), moderate (33.3% – 67.7%) and high (>67.7%). Results The elements ‘action’ and ‘condition’ in STOPP and START recommendations were rated on their clarity, resulting in 80 and 34 scores per element, respectively. The element ‘explanation’ was present in all but three (A1, A2, B11) STOPP recommendations, resulting in 77 scores. None of the START criteria contained an explanation to substantiate the prescription of potential omissions. Therefore, Likert scores for explanations were only assessed in STOPP recommendations. The agreement among the two appraisers for Likert scores was high and ranged from 76.3% (STOPP – condition) to 91.3% (STOPP – action). 44 out of 305 (14.4%) scores were replaced after consensus meetings with a third appraiser. Replacements did not alter average Likert scores per element with more than 0.2 points compared to the average scores prior to consensus. Average clarity ratings for STOPP recommendations were 65%, 60% and 67% for actions, conditions and explanations, respectively. Average clarity ratings for START recommendations were 60% and 57% for actions and conditions, respectively (Figure 1). In 80 STOPP and 34 START recommendations, the clarity ratings of 35 actions were categorized as high (30.7%), 65 as moderate (57.0%) and 14 as low (12.3%). 38 (33.3%), 67 (58.8%) and 9 (7.9%) conditions had a high, moderate or low clarity rating, respectively. In 77 STOPP criteria, the clarity ratings of 41 (53,2%) explanations were categorized as high, 35 (45.5%) as moderate and 1 (1.3%) as low. 13 STOPP criteria (C1, C2, C4, C7, D6, D12, D13, E5, E6, F1, G1, H1, H9) had high clarity ratings for all three elements. 4 START criteria (B3, G3, I1, I2) had high clarity ratings for both action and condition. Detailed information of clarity ratings per element for all individual STOPP/START-criteria can be found in Supplementary Information SI1. Elements with high (>67.7%) and moderate or low (≤67.7%) clarity ratings were analysed in more detail to identify factors that either positively or negatively affected ‘specific and unambiguous’ language most. These findings for actions, conditions and explanations with illustrative examples for STOPP and START recommendations are presented in Table 1.