The Turkish Version of the Late Life Function and Disability Instrument

The Turkish Version of the Late Life Function and Disability Instrument in Geriatric Individuals With Gonarthrosis: A Validity and Reliability Study

The aim of this study is to investigate the Turkish validity and reliability of the Late Life Function and Disability Instrument (LLFDI) and to provide a measurement tool for researchers who wish to work in this field within the Turkish literature.

Study Overview

• Status: Completed
• Conditions: Disability Physical
• Intervention / Treatment: Other: Turkish Version of the Late Life Function and Disability Instrument

Detailed Description

Short Physical Performance Battery (SPPB), Timed Up and Go Test (TUG), Functional Independence Measure (FIM), and Barthel Index of Activities of Daily Living (MBI), among others. However, these tests were designed without a clear theoretical or conceptual framework, and their utility and applicability are limited by the physical and cognitive condition of the individuals being assessed. There is a need for practical, adequate, tolerable, and reliable tests that provide consistent results and allow for a comprehensive evaluation of functional status and the effects of treatment.

Considering the existing tests, the Late Life Function and Disability Instrument (LLFDI) was developed by professors in the Department of Physical Therapy at Boston University to assess meaningful changes in both function and disability categories. The LLFDI has been translated into Hebrew, Swedish, French, Korean, Spanish, Canadian Portuguese, and Brazilian Portuguese, with its reliability and validity confirmed. This instrument is widely used in many countries worldwide.

However, there is currently no study on the Turkish version, validity, and reliability of the Late Life Function and Disability Instrument (LLFDI).

The aim of this study is to investigate the validity and reliability of the Turkish version of the Late Life Function and Disability Instrument (LLFDI) and to provide a measurement tool for researchers in this field to be used in the Turkish literature.

• Study Type: Observational
• Enrollment (Actual): 216

Contacts and Locations

Study Locations

• Turkey
  • Istanbul, Turkey, 34010
    • Istanbul Okan University

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Older Adult
• Accepts Healthy Volunteers: No

• Sampling Method: Non-Probability Sample

Study Population

The study population consists of individuals aged 65 and older who have been diagnosed with gonarthrosis. Participants must be able to read and write in Turkish, have no neurological problems, and score above 20 points on the Mini-Mental Test. Only volunteers who meet the inclusion criteria will be included in the study

Description

Inclusion Criteria:

• over 65 years old,
• being willing and volunteer to participate in the study,
• having reading and writing skills,
• being able to read and write in Turkish,
• having a diagnosis of gonarthrosis, and
• scoring above 20 points on the Mini-Mental Test.

Exclusion Criteria:

• Having a neurological problem

Study Plan

How is the study designed?

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Patient Assessment Form	The form, prepared by the researcher, consists of 18 questions aimed at obtaining information on the sociodemographic characteristics of patients. Sociodemographic characteristics include address, age, gender, height, body weight, occupation, education level, social security status, marital status, and dominant hand. Additionally, fall history, medical history, family history, and use of assistive devices will be recorded to obtain general health information.	Baseline
Mini-Mental Test (MMT)	The Mini-Mental Test (MMT) is widely used in clinical practice for detecting cognitive impairments, monitoring the progression of dementia syndromes, and assessing responses to treatment. It is also used in epidemiological studies involving elderly individuals living in the community or in institutions. The test consists of 11 items grouped under five main sections: Orientation Registration memory Attention and calculation Recall Language The total score is 30 points, and it is one of the most commonly used tests for detecting dementia. It was first described by Folstein (1975) and later refined by Molloy et al. (1991). The test has been validated and found to be reliable in the Turkish population. However, since it was initially applicable only to educated elderly individuals, it was revised in 2008 by Keskinoglu et al. to ensure its validity and reliability for both educated and uneducated elderly populations.	Baseline
Late Life Function and Disability Instrument	The Late Life Function and Disability Instrument (LLFDI) was developed to assess significant changes in functional and disability categories. The function component consists of 32 questions and is evaluated in three domains: Upper extremity function (7 questions: F1, F3, F5, F6, F13, F16, F17) Basic lower extremity function (14 questions: F2, F10, F11, F12, F14, F15, F18, F21, F22, F23, F25, F26, F28, F31) Advanced lower extremity function (11 questions: F4, F7, F8, F9, F19, F20, F24, F27, F29, F30, F32) Each question is scored using a 5-point rating scale. The disability component consists of 16 questions, evaluated in two dimensions: Frequency Limitation Both dimensions use a 5-point rating scale. The total score of the scale is 100, with higher scores indicating better functional status. The scale was originally developed in the United States by Jette et al. in 2002	Baseline
Barthel Activities of Daily Living Index	The Barthel Index assesses an individual's ability to perform daily activities independently, such as: Eating Using the toilet Bathing Moving indoors and outdoors The total score is 100, and the dependency levels are classified as follows: 0-20 points → Completely dependent 21-61 points → Severely dependent 62-90 points → Moderately dependent 91-99 points → Mildly dependent 100 points → Fully independent The Barthel Index (BI) was developed by Mahoney and Barthel in 1965. The validity and reliability of its Turkish version were studied by Küçükdeveci et al. in 2000	Baseline
Functional Independence Measure	The Functional Independence Measure (FIM) evaluates an individual's ability to perform daily activities independently in two domains: Motor Cognitive The total score is 126, and each item is rated as follows: 7 points → Fully independent 6 points → Modified independence 5 points → No physical assistance needed, only verbal cues 4 points → Minimal assistance (the patient performs at least 75% of the effort) 3 points → Moderate assistance (50-75% effort by the patient) 2 points → Maximum assistance (25-50% effort by the patient) 1 point → Total assistance The scale was first developed by Karyl et al. in 1993	Baseline
Lequesne Algofunctional Knee Index	The Lequesne Algofunctional Knee Index is designed to evaluate patients with gonarthrosis and consists of three main components: Pain or discomfort Maximum walking distance Activities of daily living The total score is 24: For the first and second sections, scores range from 0 (no pain or functional limitation) to 8 (severe pain or functional limitation). The maximum walking distance section is scored from 0 (no limitation) to 6 (walking less than 100 m). If the patient uses one cane or crutch, 1 point is added; if they use two canes or crutches, 2 points are added. Higher scores indicate worse health status. This index was developed by Lequesne et al. in 1987	Baseline

Collaborators and Investigators

• Sponsor: Okan University

Study record dates

Study Major Dates

• Study Start (Actual): March 10, 2025
• Primary Completion (Actual): April 15, 2025
• Study Completion (Actual): April 19, 2025

Study Registration Dates

• First Submitted: February 22, 2025
• First Submitted That Met QC Criteria: March 4, 2025
• First Posted (Actual): March 5, 2025

Study Record Updates

• Last Update Posted (Actual): April 24, 2025
• Last Update Submitted That Met QC Criteria: April 19, 2025
• Last Verified: April 1, 2025

More Information

Terms related to this study

• Keywords: validity; disability; reliability
• Other Study ID Numbers: 014 (Other Identifier: Nahrain Medical Research Collective (NMRC))

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No