Authors (including presenting author) :
Cheung RWM, Kong CK, Cheuk TK, Cheung TY, Pang TC, Mak WM, Tai HM, Yiu WY
Affiliation :
S.K. Yee School of Health Sciences, Saint Francis University
Keyword 2: :
Ishii test screening tool
Keyword 3: :
Intra-rater reliability
Keyword 4: :
Middle-aged adults
Keyword 5: :
Handgrip strength
Keyword 6: :
Calf circumference
Introduction :
The European Working Group on Sarcopenia in Older People (EWGSOP2) defines sarcopenia as a progressive decline in muscle mass and strength influenced by factors beyond aging. It is linked to poor quality of life and higher risks of falls, fractures, and mortality, highlighting the need for early identification and intervention. Muscle strength decreases about 15% annually after age 50, with recent studies showing severe sarcopenia prevalence in Western China at 3.55% in men and 4.43% in women under 60. This underscores the importance of early community screening in the 45–59 age group, consistent with the World Health Organization's definition of middle adulthood. EWGSOP2 recommends using simple, cost-effective tools for screening, such as the Ishii Test, which assesses sarcopenia using age, handgrip strength (HGS), and calf circumference (CC). The Ishii Test demonstrates high diagnostic accuracy for identifying sarcopenia and predicting one-year mortality in hospitalized older adults. However, its reliability in middle-aged populations has not been explored. Consistent measurements are vital for accurate diagnoses and monitoring, prompting this study to evaluate the intra-rater reliability of the Ishii Test in middle-aged individuals.
Objectives :
To evaluate the within-day intra-rater reliability of the Ishii Test, including its individual components (HGS and CC), for sarcopenia screening in healthy middle-aged adults (aged 45–59).
Methodology :
A prospective observational study utilized a two-instance repeated-measures design to evaluate the within-day intra-rater reliability of the Ishii Test and its components (HGS and CC) in healthy middle-aged adults, following COnsensus-based Standards for the selection of health Measurement INstruments (COSMIN) and Guidelines for Reporting Reliability and Agreement Studies. Ten healthy participants aged 45–59 were recruited by convenience sampling from the community. Each participant was assessed twice, separated by 15 minutes on the same day in a controlled laboratory environment, by the same year-4 physiotherapy student, supervised by a registered physiotherapist, HGS and CC were measured according to the validation study of the Ishii Test, using a Jamar® Plus+ Digital Hand Dynamometer and a steel measuring tape, respectively. For HGS measurement, a standardized seated posture was adopted for three maximal attempts per hand with 3-second contractions and 15-second rests, the maximal value across six trials alternating between both hands was used for statistical analysis. For CC measurement, the largest circumference of the non-dominant lower leg was taken in barefoot standing with feet shoulder-width apart. Ishii scores were computed after each session, in males, the scores were calculated as 0.62 × (age − 64) − 3.09 × (HGS − 50) − 4.64 × (CC − 42), while in females, the scores were calculated as 0.80 × (age − 64) − 5.09 × (HGS − 34) − 3.28 × (CC− 42). Standardized pre-test guidance and safety monitoring were provided; adverse events, if any, were documented. The research question centred on the within-day intra-rater reliability of the Ishii Test in the target population. It was hypothesized that Ishii Test and its components would demonstrate excellent reliability, with intraclass correlation coefficient (ICC) ≥ .90. Statistical analyses were conducted using the Statistical Package for the Social Sciences (SPSS), with statistical significance set at p ≤ .05. Data normality was assessed with Shapiro-Wilk test. ICC at 95% confidence interval (two-way mixed effects, absolute agreement, single rater) was calculated to determine the consistency between repeated measurements for relative reliability, interpreted as poor (0–.49), moderate (.50–.74), good (.75–.89), or excellent (.90–1) level of agreement according to the guideline, while standard error of measurement (SEM), minimal detectable change at 95% confidence interval (MDC95), and Bland-Altman analyses were used to quantify the absolute reliability.
Result & Outcome :
Establishment for reliability is essential for measurement tools to be used clinically. To our understanding, our study was the first reliability study for the Ishii Test as a sarcopenia screening tool in a healthy middle-aged population. The primary outcome, the Ishii Test, demonstrated excellent within-day intra-rater relative reliability (ICC = .980). Meanwhile, its individual components, HGS (ICC = .989) and CC (ICC = .999), also exhibited excellent intra-rater relative reliability. Establishment for reliability is essential for measurement tools to be used clinically. To our understanding, our study was the first reliability study for the Ishii Test as a sarcopenia screening tool in a healthy middle-aged population. The primary outcome, the Ishii Test, demonstrated excellent within-day intra-rater relative reliability (ICC = .980). Meanwhile, its individual components, HGS (ICC = .989) and CC (ICC = .999), also exhibited excellent intra-rater relative reliability. These statistically significant findings (all p-value < .001) supported the hypothesis and confirmed that the Ishii Test was a highly consistent and reproducible tool under these conditions. Our study reflected moderate to excellent absolute reliability. The SEM for the Ishii Test score was 4.22 points, 0.93 kgf for HGS and 0.12 cm for CC, while the MDC95 for the Ishii Test score was 11.71 points, suggesting that a change exceeding 11.71 points can be considered a true change with 95% confidence, rather than measurement error, same interpretation was applied the to MDC95 values for HGS and CC as 2.58 kgf and 0.33 cm respectively. This provided specific thresholds to confidently detect real changes in muscle strength and size during follow-up assessments. This study has demonstrated that the Ishii Test enhances adoption in the community. It can be used for early screening of sarcopenia in primary healthcare settings, promote academic education on sarcopenia screening, and facilitate its application in primary healthcare for sarcopenia prevention in middle-aged people worldwide. These lead to a better management of sarcopenia through early interventions.
