Secular trends in age at menarche in 20th century Mexico: Differences by ethnicity, area of residency, and socioeconomic status.

Objectives: This study aims to assess the secular trend in age at menarche (AAM) in Mexico over the 20th century, and compare the patterns according to area of residence (rural/urban), socioeconomic status (SES), and ethnicity (indigenous/nonindigenous).

Methods: Data on AAM from 24 380 women aged ≥20 years born between 1906 and 1986 were obtained from the Mexican National Health and Nutrition Survey 2006. Birth cohorts were compared to test for a secular trend and differences in mean AAM by area of residence, SES, and ethnicity were evaluated using the Welch test for heterogeneous variances followed by Tamhane T for post hoc comparisons.

Verbal fluency in Mexican Spanish-speaking subjects with high educational level: Ranking of letters and semantic categories.

: Verbal fluency tasks are useful tools in clinical practice and research studies across languages and contexts, but specific data obtained using Spanish phonological tasks and semantic tasks with different levels of difficulty are lacking. The present study aimed to determine the difficulty level of a phonological tasks and semantic tasks among Spanish-speakers. : Both tasks were ordered across five difficulty levels based on the frequency of use in Mexican Spanish (phonological) and the number of elements given by a group of participants (semantic).