Patient-Reported Sleep vs Objective Sleep and Physical Activity Measures in Ankylosing Spondylitis: A Pre-Post Study

Evaluation of Sleep Quality and Physical Activity According to Disease Activity Periods in Ankylosing Spondylitis

Eighteen patients with active ankylosing spondylitis were evaluated at initiation of anti-TNF-α therapy and again after 4 months. Subjective sleep quality was assessed using the Pittsburgh Sleep Quality Index (PSQI). Objective sleep parameters were measured by overnight polysomnography, and physical activity was assessed using a multi-sensor wearable accelerometer. Clinical outcomes included BASDAI/BASFI, ASQoL, and HADS. This was a prospective, single-arm pre-post pilot study

Study Overview

• Status: Completed
• Conditions: Physical Activity; Sleep Quality; Ankylosing Spondylitis (AS)

Detailed Description

Objective: This prospective, single-arm pre-post pilot study characterized patient-reported and objective sleep and physical activity measures in patients with active ankylosing spondylitis (AS) who were planned to start anti-TNF-α therapy as part of routine clinical care despite use of at least two NSAIDs. The primary purpose was to evaluate sleep and physical activity in relation to disease activity periods, rather than to test a prespecified treatment effect.

Design and Participants: Eighteen adults fulfilling the modified New York criteria (mNYC) and classified as active based on BASDAI were enrolled. Assessments were performed at baseline (prior to starting anti-TNF-α therapy) and repeated at 4 months.

Assessments: At both time points, participants completed patient-reported questionnaires and underwent objective measurements. Subjective sleep quality was measured using the Pittsburgh Sleep Quality Index (PSQI). Objective sleep was assessed by overnight polysomnography (PSG), and physical activity was assessed using a multi-sensor wearable accelerometer (SenseWear Armband, BodyMedia Inc., Pittsburgh, PA, USA). Clinical and psychosocial measures included BASDAI, BASFI, BASMI, ASQoL, and HADS (anxiety and depression). Given the exploratory aim and limited sample size, anti-TNF agent subtypes were not specified in the registry record.

Primary Outcome (PSG): The primary outcome measure was sleep efficiency (%) derived from PSG, assessed at baseline and at 4 months.

Additional PSG parameters included time in bed, sleep period time, total sleep time, stage durations (N1, N2, N3, and REM), arousal index, periodic limb movement index, apnea events, and apnea-hypopnea index (AHI). Wearable-derived parameters included total energy expenditure (kcal/day), total step count (steps/hour), total sedentary time (min/hour), sleep duration (min/hour), and physical activity duration (min/hour).

Statistical Analysis: Distribution of continuous variables was assessed using the Shapiro-Wilk test. Non-normally distributed data were summarized as median (Q1-Q3). Pre-post comparisons were performed using the Wilcoxon signed-rank test. Exploratory Spearman rank correlations examined associations between changes in PSQI subscales and changes in BASDAI, BASFI, BASMI, ASQoL, HADS, and wearable-derived activity parameters. Multiple comparisons were controlled within hypothesis families using the Benjamini-Hochberg false discovery rate (FDR) procedure (FDR-adjusted p<0.05). For sleep efficiency, the Hodges-Lehmann pseudo-median difference and 95% confidence interval were calculated in R; primary analyses were performed in SPSS (v24).

• Study Type: Observational
• Enrollment (Actual): 18

Participation Criteria

Eligibility Criteria

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

• Sampling Method: Non-Probability Sample

Study Population

A total of 18 patients with active ankylosing spondylitis who met the modified New York criteria (mNYC) were enrolled in this prospective study. Disease activity was assessed using the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI). Patients were eligible if they had persistent active disease despite treatment with at least two NSAIDs and if anti-TNF-α therapy was planned as part of routine clinical care. Patients who agreed to participate in the study and provided informed consent were included.

Description

Inclusion Criteria:

• Adults with active ankylosing spondylitis (AS) meeting the modified New York criteria (mNYC)
• Active disease defined as BASDAI ≥ 4.
• Inadequate response despite use of at least two NSAIDs (per routine clinical decision to initiate anti-TNF-α).
• Biologic-naïve (no prior anti-TNF/biologic therapy).

Exclusion Criteria

• History of a sleep disorder.
• Use of medications that affect sleep.
• Diagnosis of fibromyalgia.
• Presence of upper airway anatomical obstruction.

Study Plan

How is the study designed?

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort
AS Patients (Pre-Post; Patients with ankylosing spondylitis receiving routine anti-TNF therapy; assessments were performed before and after treatment."

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Sleep efficiency	Sleep efficiency measured by overnight polysomnography.	Baseline and 4 months.

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Daily Step Count	Daily step count (steps/day) measured with the SenseWear Armband (multi-sensor accelerometer). The device was worn on the non-dominant arm for 3 consecutive days at each assessment; the outcome is the average steps/day across the 3 days. Wear-time compliance required wearing the device for ≥90% of the prescribed period.	Baseline and 4 months.
Pittsburgh Sleep Quality Index (PSQI) total score	Self-reported sleep quality assessed using the PSQI; total score range 0-21, with higher scores indicating worse sleep quality.	Baseline and 4 months.

Collaborators and Investigators

• Sponsor: Samsun University

Study record dates

Study Major Dates

• Study Start (Actual): August 1, 2015
• Primary Completion (Actual): October 31, 2016
• Study Completion (Actual): October 31, 2016

Study Registration Dates

• First Submitted: February 18, 2026
• First Submitted That Met QC Criteria: February 25, 2026
• First Posted (Actual): February 27, 2026

Study Record Updates

• Last Update Posted (Actual): February 27, 2026
• Last Update Submitted That Met QC Criteria: February 25, 2026
• Last Verified: February 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Axial Spondyloarthritis; Bone Diseases; Musculoskeletal Diseases; Nervous System Diseases; Mental Disorders; Arthritis; Joint Diseases; Spinal Diseases; Spondylarthropathies; Ankylosis; Sleep Wake Disorders; Sleep Disorders, Intrinsic; Dyssomnias; Spondylarthritis; Spondylitis; Behavior; Spondylitis, Ankylosing; Sleep Initiation and Maintenance Disorders; Motor Activity
• Other Study ID Numbers: 24237859-2015/80

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO
• IPD Plan Description: Individual participant data will not be shared due to privacy and confidentiality considerations and institutional restrictions

Drug and device information, study documents

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