Clinical symptoms, signs and tests for identification of impending and current water‐loss dehydration in older people

Background There is evidence that water‐loss dehydration is common in older people and associated with many causes of morbidity and mortality. However, it is unclear what clinical symptoms, signs and tests may be used to identify early dehydration in older people, so that support can be mobilised to improve hydration before health and well‐being are compromised. Objectives To determine the diagnostic accuracy of state (one time), minimally invasive clinical symptoms, signs and tests to be used as screening tests for detecting water‐loss dehydration in older people by systematically reviewing studies that have measured a reference standard and at least one index test in people aged 65 years and over. Water‐loss dehydration was defined primarily as including everyone with either impending or current water‐loss dehydration (including all those with serum osmolality ≥ 295 mOsm/kg as being dehydrated). Search methods Structured search strategies were developed for MEDLINE (OvidSP), EMBASE (OvidSP), CINAHL, LILACS, DARE and HTA databases (The Cochrane Library), and the International Clinical Trials Registry Platform (ICTRP). Reference lists of included studies and identified relevant reviews were checked. Authors of included studies were contacted for details of further studies. Selection criteria Titles and s were scanned and all potentially relevant studies obtained in full text. Inclusion of full text studies was assessed independently in duplicate, and disagreements resolved by a third author. We wrote to authors of all studies that appeared to have collected data on at least one reference standard and at least one index test, and in at least 10 people aged ≥ 65 years, even where no comparative analysis has been published, requesting original dataset so we could create 2 x 2 tables. Data collection and analysis Diagnostic accuracy of each test was assessed against the best available reference standard for water‐loss dehydration (serum or plasma osmolality cut‐off ≥ 295 mOsm/kg, serum osmolarity or weight change) within each study. For each index test study data were presented in forest plots of sensitivity and specificity. The primary target condition was water‐loss dehydration (including either impending or current water‐loss dehydration). Secondary target conditions were intended as current (> 300 mOsm/kg) and impending (295 to 300 mOsm/kg) water‐loss dehydration, but restricted to current dehydration in the final review. We conducted bivariate random‐effe