9 The MLQ was added to the SAGE study with the 2013 follow-up survey. More details about the SAGE study methodology have been reported previously. Cognitive assessments were conducted using a brief telephone interview, while other instruments were sent to the participants using postal or electronic mail. The sample was recruited using random digit dialing on landline home telephones. The study was approved by the Human Research Protections Program at University of California San Diego. Participants were excluded if they resided in a nursing home or needed daily skilled nursing care, reported a formal diagnosis of dementia made by a clinician, and/or had a terminal illness or need for hospice care. Inclusion criteria for SAGE were 1) ages 21 and older 2) a (landline) telephone in the home, 3) physical and mental ability to participate in a telephone interview and to complete an online or paper-and-pencil mail survey, 4) informed consent for study participation, and 5) English fluency. The SAGE study used a structured multicohort longitudinal design to recruit 1,300 community-dwelling residents of San Diego County, CA, from age 21 to 100+, with an oversampling of people over age 75 because of their under-representation in the published literature as well as a greater risk of drop-outs due to death and disability. In addition, we explored the relationship of meaning in life with age and other sociodemographic factors.

We explored the relationship of search for meaning to functioning as the literature on Search is far less uniform than that on Presence. We hypothesized that presence of meaning would be associated with better physical, mental, and cognitive functioning. 9, 10 We used MLQ to assess meaning in life. We used cross-sectional data from the Successful AGing Evaluation (SAGE) study, which includes a community-dwelling sample of randomly selected individuals across the entire adult lifespan. In the present study we sought to remedy some of these limitations. 4, 6, 7 Many studies also create arbitrary age-categories which further restrict analysis. 1, 7 Nearly all of these studies also restrict their analyses to linear relationships, and the possibility of non-linear relationships is not explored. 4 Many other studies either excluded older subjects or included very few of them. For instance, in one frequently cited study of meaning across the lifespan with a large sample of nearly 8,800 subjects, only 163 subjects (1.8%) were 65 years of age or older.

2 While multiple studies have examined the relationship with physical and mental functioning, the association of meaning in life and cognitive functioning is less well-studied in cognitively unimpaired adults.ДЄ noteworthy limitation of existing research in this area is the under-representation of older subjects. 1, 3, 4, 6вЂ“ 8 The positive association of meaning in life with physical functioning has also been extensively investigated in the literature. 1, 3, 4, 6вЂ“ 8 These studies also suggest a positive association of presence of meaning and a negative association of search for meaning with mental functioning. 1, 4, 6, 7 Existing literature generally suggests that Presence increases with age and Search decreases with age, and there is an inverse relationship between Presence and Search, but the results have not always been consistent across studies. The relationship between age and meaning in life has been examined in a number of prior reports. Search refers to an active pursuit of meaning in oneвЂ™s life. Presence refers to the perception that oneвЂ™s life is meaningful.

It assesses two different dimensions of meaning in life: presence of meaning (Presence) and search for meaning (Search). 4, a scale with good psychometric properties that has been successfully validated and applied in various cultural settings across the world. One popular instrument to assess meaning in life is the Meaning in Life Questionnaire (MLQ) by Steger et al. 1вЂ“ 4 A recent US cohort study of nearly 7,000 older adults demonstrated that stronger purpose in life was associated with lower mortality. A body of literature on this subject shows that individuals who perceive their lives to be more meaningful have better outcomes across a wide variety of psychological and physical measures of health and well-being. Over the last three decades, meaning in life has emerged as an important focus of study in medical research, especially in the context of the aging population.

Across meaning