E National Institute of Health, USA http://privacyruleandresearch.nih.gov/research_repositories.asp).Measures and harmonizationOf the 11 contributing studies, nine provided raw data needed to make classifications of MCI (summarized in S1 5 Tables). The Sydney team processed these data, which were harmonized, when necessary, and TF14016 dose pooled. The other two studies, CFAS and Invece.Ab, conducted analyses in-house using the protocols developed for this report. Baseline or wave 1 data were used for all studies except two that did not have all variables needed to make MCI classifications until later waves: jir.2010.0097 MoVIES [27] provided data for wave 2 (2 years after baseline), and PATH [28] for wave 3 (8 years after baseline). Data for SLAS are for two cohorts, SLAS-1 recruited 2003?004 and SLAS-2 recruited 2008?011, and for whom the same core measurements and procedures were used [29, 30].DemographicsInformation included age, sex and education. Education data were harmonized by forming a variable with four categories: Less than high school completion; high school completion; technical or college diploma; university degree (as shown in S6 Table). Note that we use the term college diploma in an international context, referring to courses of less duration and standard than a bachelor’s degree that are typically provided by technical, applied, or more vocationally oriented institutions rather than universities. Each of the contributing studies helped determine how the data representing their local education system was best transformed to the four categories we used.Functional abilityA variety of instruments assessing ADLs and instrumental ADLs (IADLs) was used across the studies (S7 Table), with the Lawton Brody IADL Scale [35] used by five studies. Six common and Nilotinib biological activity compatible IADL items were chosen for harmonization: telephone, food preparation, medications, shopping, finances, and transport. For each of these items, the Lawton Brody IADL Scale assigns a score of 0 to dependent responses and 1 to independent responses. We produced a dichotomized variable of 0 (dependence) and 1 (independence) for each item by matching responses from different instruments to this scoring system. The strictness or level of assistance required for a classification of dependence varies between items on the Lawton Brody Scale, and thus a response from another instrument such as “Yes, some difficulty” could be considered independent on journal.pone.0158910 one of the harmonized items but dependent on another. For full details of this procedure see S8 and S9 Tables.Cognitive ability or statusAll studies, except for ZARADEMP, administered a neuropsychological test battery; additionally, all except for EAS and WHICAP used the Mini-Mental State Examination (MMSE). However, EAS administered the Blessed Information-Memory-Concentration test, and a validated formula was used to convert scores for this test to MMSE scores [36]. More than half of the studies administered the CDR Scale (Table 3). There was limited overlap in the neuropsychological tests used between studies, and each test score was allocated to one of five cognitive domains: memory, attention/processing speed, language, executive function, and perceptualmotor. However, the perceptual-motor domain was not used in classifying MCI as scores could not be formed for four studies (ESPRIT, HK-MAPS, Invece.Ab, and PATH). Tests werePLOS ONE | DOI:10.1371/journal.pone.0142388 November 5,5 /Mild Cognitive Impairment InternationallyTable 3. Prevalence.E National Institute of Health, USA http://privacyruleandresearch.nih.gov/research_repositories.asp).Measures and harmonizationOf the 11 contributing studies, nine provided raw data needed to make classifications of MCI (summarized in S1 5 Tables). The Sydney team processed these data, which were harmonized, when necessary, and pooled. The other two studies, CFAS and Invece.Ab, conducted analyses in-house using the protocols developed for this report. Baseline or wave 1 data were used for all studies except two that did not have all variables needed to make MCI classifications until later waves: jir.2010.0097 MoVIES [27] provided data for wave 2 (2 years after baseline), and PATH [28] for wave 3 (8 years after baseline). Data for SLAS are for two cohorts, SLAS-1 recruited 2003?004 and SLAS-2 recruited 2008?011, and for whom the same core measurements and procedures were used [29, 30].DemographicsInformation included age, sex and education. Education data were harmonized by forming a variable with four categories: Less than high school completion; high school completion; technical or college diploma; university degree (as shown in S6 Table). Note that we use the term college diploma in an international context, referring to courses of less duration and standard than a bachelor’s degree that are typically provided by technical, applied, or more vocationally oriented institutions rather than universities. Each of the contributing studies helped determine how the data representing their local education system was best transformed to the four categories we used.Functional abilityA variety of instruments assessing ADLs and instrumental ADLs (IADLs) was used across the studies (S7 Table), with the Lawton Brody IADL Scale [35] used by five studies. Six common and compatible IADL items were chosen for harmonization: telephone, food preparation, medications, shopping, finances, and transport. For each of these items, the Lawton Brody IADL Scale assigns a score of 0 to dependent responses and 1 to independent responses. We produced a dichotomized variable of 0 (dependence) and 1 (independence) for each item by matching responses from different instruments to this scoring system. The strictness or level of assistance required for a classification of dependence varies between items on the Lawton Brody Scale, and thus a response from another instrument such as “Yes, some difficulty” could be considered independent on journal.pone.0158910 one of the harmonized items but dependent on another. For full details of this procedure see S8 and S9 Tables.Cognitive ability or statusAll studies, except for ZARADEMP, administered a neuropsychological test battery; additionally, all except for EAS and WHICAP used the Mini-Mental State Examination (MMSE). However, EAS administered the Blessed Information-Memory-Concentration test, and a validated formula was used to convert scores for this test to MMSE scores [36]. More than half of the studies administered the CDR Scale (Table 3). There was limited overlap in the neuropsychological tests used between studies, and each test score was allocated to one of five cognitive domains: memory, attention/processing speed, language, executive function, and perceptualmotor. However, the perceptual-motor domain was not used in classifying MCI as scores could not be formed for four studies (ESPRIT, HK-MAPS, Invece.Ab, and PATH). Tests werePLOS ONE | DOI:10.1371/journal.pone.0142388 November 5,5 /Mild Cognitive Impairment InternationallyTable 3. Prevalence.