Background This study investigated the prevalence of frailty as well as its association with multimorbidity among older adults living in the South of Germany.

Methods 1079 participants aged 65 years and older were interviewed and took part in a physical examination in the KORA-Age survey. Frailty was defined by weight loss, exhaustion, low physical activity, slow gait speed, and reduced grip strength. Participants were classified as non-frail, pre-frail, and frail if they met 0, 1 or 2, and 3 or more criteria, respectively. Multimorbidity was defined in three groups, group 1 with no disease, group 2 with one or two diseases, and group 3 with more than three out of nine disease groups. Multivariable logistic regression analyses adjusted for malnutrition, alcohol intake, education and body mass index were performed.

Results The age standardised prevalence of frailty and pre-frailty combined was 35.6% (95% CI 31.1 to 40.0) for male and 38.5% (95% CI 34.1 to 42.8) for female participants. Prevalence of frailty increased with age from 24.1% in the 65–69 year olds to 78.0% in the over 85 year olds for men (20.7% to 79.3% in women). The risk for being frail increased with higher multimorbidity scores (OR 1.9, 95% CI 1.4 to 2.6 for group 2 and OR 3.3, 95% CI 1.8 to 6.0 for group 3 each compared to group 1) after adjustment for covariables. 27.8% of pre-frail and frail persons had no disease.

Conclusion These data indicate that frailty is strongly associated with multimorbidity. Examinations of the course of frailty and its determinants are underway.