Multiple Sclerosis Intimacy and Sexuality Questionnaire-15

1. Abstract

The Multiple Sclerosis Intimacy and Sexuality Questionnaire-15 (MSISQ-15) is a specialized, brief, patient-reported psychometric instrument engineered to quantify and characterize the multifaceted nature of sexual dysfunction in individuals diagnosed with multiple sclerosis (MS). Chronic demyelinating neurodegenerative pathology frequently disrupts intimate partnerships and physiologic sexual functioning, yet these impairments remain consistently under-identified in clinical neurology and rehabilitation. Derived as an abbreviated, psychometrically refined adaptation of the original 19-item Multiple Sclerosis Intimacy and Sexuality Questionnaire (MSISQ-19), the MSISQ-15 operationalizes sexual health through a tri-partite conceptual architecture comprising primary (direct neurogenic lesions within the central nervous system), secondary (indirect physical consequences, symptomatology, and therapeutic side effects), and tertiary (psychosocial, affective, and interpersonal sequelae) sexual dysfunction.

Composed of 15 self-administered items scored on a 5-point Likert metric ranging from 1 to 5, the instrument yields a dimensional total score ranging between 15 and 75, alongside three balanced subscale scores corresponding to each conceptual tier. International psychometric investigations across diverse cross-cultural cohorts—most notably including comprehensive structural evaluations and cultural adaptations in Spain, the United States, France, Italy, Turkey, Greece, and Poland—demonstrate robust empirical properties. Confirmatory factor analyses utilizing estimation strategies appropriate for categorical indicators consistently affirm the three-factor latent structure (e.g., Comparative Fit Index [CFI] = 0.970, Tucker-Lewis Index [TLI] = 0.960, Root Mean Square Error of Approximation [RMSEA] = 0.070). Internal consistency estimates remain elevated across cohorts, with global ordinal alpha coefficients frequently reaching 0.89 and domain-level coefficients spanning 0.81 to 0.87. Demonstrating convergent validity against domain-specific measures such as the Male Sexual Function (FSH) and Female Sexual Function-2 (FSM-2) scales, divergent validity against general dyadic adjustment metrics, and meaningful sensitivity to quality-of-life decrements, the MSISQ-15 constitutes an indispensable diagnostic and evaluative tool across clinical neuro-rehabilitation and empirical health psychology.

2. Keywords

Multiple Sclerosis, Sexual Dysfunction, MSISQ-15, Intimacy, Psychometrics, Biopsychosocial Model, Neuro-rehabilitation, Confirmatory Factor Analysis, Quality of Life, Health Psychology, Primary Sexual Dysfunction, Secondary Sexual Dysfunction, Tertiary Sexual Dysfunction

3. Authors

The brief 15-item revision of the MSISQ was spearheaded by Dr. Frederick W. Foley and colleagues, emerging from foundational clinical and psychometric research conducted within the United States (Foley et al., 2013). Dr. Foley is affiliated with the Ferkauf Graduate School of Psychology at Yeshiva University (Bronx, NY, United States) and has served as a preeminent authority in psychological aspects of multiple sclerosis care and intimacy preservation.

The formal cross-cultural translation, linguistic validation, and psychometric adaptation into Spanish—which substantiated the structural parameters referenced herein—was directed by an interdisciplinary investigative team based at the University of Alicante (San Vicente del Raspeig, Alicante, Spain):

• Antonio Esteve-Ríos, PhD, RN: Department of Nursing, Faculty of Health Sciences, University of Alicante, Spain.
• María José Cabañero-Martínez, PhD, RN: Department of Nursing, Faculty of Health Sciences, University of Alicante, Spain (Corresponding Author: [email protected]).
• Silvia Escribano, PhD, RN: Department of Nursing, Faculty of Health Sciences, University of Alicante, Spain.
• Frederick W. Foley, PhD: Ferkauf Graduate School of Psychology, Yeshiva University, Bronx, NY, United States of America.
• Sofía García-Sanjuán, PhD, RN: Department of Nursing, Faculty of Health Sciences, University of Alicante, Spain.

4. Purpose

The core clinical and scientific imperative underlying the creation and worldwide deployment of the MSISQ-15 is the systematic elimination of barriers to diagnosing, understanding, and managing intimacy impairments in patients with chronic central nervous system diseases. Epidemiological investigations demonstrate that between 50% and 90% of men and 40% to 80% of women living with multiple sclerosis experience chronic alterations in sexual response, intimate connection, or reproductive health. Despite this marked prevalence, sexual dysfunction remains one of the most under-addressed complications of demyelinating illness. The clinical interaction often suffers from mutual avoidance: patients often feel reticent or embarrassed to raise concerns regarding their intimacy, while clinicians face acute time constraints, diagnostic ambiguity, and a lack of structured assessment apparatus, frequently prioritizing ambulatory, visual, or cognitive endpoints.

The MSISQ-15 resolves these clinical barriers by serving multiple distinct functions:

• Standardized Diagnostic Screening: It provides an efficient, self-administered inventory that patients can complete independently, normalizing sexual symptom reporting and initiating sensitive dialogues between healthcare professionals and patients.
• Etiological Triangulation: Unlike generic sexual function instruments (e.g., the International Index of Erectile Function or the Female Sexual Function Index), the MSISQ-15 is structured specifically around neurodegenerative sequelae. It isolates whether intimate impairment arises from focal demyelination within spinal or supraspinal pathways, secondary physical disability, or psychological distress.
• Guiding Interdisciplinary Intervention: Because the MSISQ-15 delineates symptoms into distinct operational domains, multidisciplinary rehabilitation teams can allocate clinical resources accurately. Neurological causes may require pharmacotherapy (e.g., phosphodiesterase-5 inhibitors, topical sensory stimulants), secondary causes require physical therapy or symptom management (e.g., antispasmodics, fatigue management, bladder training), and tertiary causes indicate psychotherapy, cognitive behavioral interventions, or sex therapy.
• Clinical Trial Endpoint: The instrument supplies empirical researchers with a responsive, methodologically sound outcome metric to evaluate the therapeutic efficacy of novel disease-modifying therapies, symptomatic pharmacotherapies, and psycho-educational rehabilitation protocols.

5. Psychological Construct

The psychological and physiological construct measured by the MSISQ-15 is Multiple Sclerosis-Related Sexual Dysfunction. Within this psychometric framework, sexual health is conceptualized as an integrated biopsychosocial state vulnerable to disruption along multiple pathophysiological vectors. The construct does not treat sexual functioning as a simple mechanical reflex, but rather as an evolving continuum of physiological responsiveness, bodily mechanics, affective state, body image, and relational adjustment. The construct is operationalized into three distinct, interdependent dimensions:

Primary Sexual Dysfunction (Items 1–5)

This subscale assesses the direct consequence of central nervous system demyelination and axonal transection within the neural pathways that orchestrate human sexual response. Structural lesions situated in the brainstem, cerebral cortex, or the sacral, lumbar, and thoracic segments of the spinal cord interrupt autonomic and somatic reflex arcs. Specific manifestations measured by this dimension include:

• Sensory Hypoesthesia or Paresthesia: Marked diminution, numbness, or altered qualitative sensation across the genital and perineal dermatomes.
• Erectile and Lubrication Difficulties: Failure of parasympathetically mediated vascular engorgement, leading to insufficient vaginal lubrication in women or difficulties initiating and sustaining penile erections in men.
• Anorgasmia and Delayed Climax: Interruption of ascending and descending pathways coordinating sympathetic, somatic, and cerebral activation necessary for orgasm, resulting in severe orgasmic delay or total anorgasmia.
• Reduced Libido: Neurologically mediated attenuation of innate sexual desire and subjective arousal.

Secondary Sexual Dysfunction (Items 6–10)

This subscale evaluates the indirect sexual barriers generated by broader MS-related physical symptomatology and medical therapies that are not intrinsically sexual in nature, but physically compromise intimacy. Symptoms captured within this dimension include:

• Musculoskeletal Spasticity and Contractures: Involuntary muscle spasms, adductor tightness, and painful hypertonia in the lower extremities, torso, or pelvic girdle that impede sexual positioning or cause mechanical distress during intercourse.
• Neuropathic and Musculoskeletal Pain: Central neuropathic dysesthesias, burning sensations, or pelvic allodynia during physical contact.
• Motor Weakness: Profound generalized paresis or focal extremity weakness that diminishes endurance and physical mobility during intimacy.
• Intractable Fatigue: Central neurogenic exhaustion, distinct from normal tiredness, which severely depletes the energy reserves necessary for sexual activity.
• Neurogenic Bladder and Bowel Dysfunction: Urinary urgency, nocturia, bowel dyssynergia, or incontinence fears during sexual intercourse.

Tertiary Sexual Dysfunction (Items 11–15)

This subscale examines the affective, cognitive, interpersonal, and sociocultural sequelae of managing a chronic, unpredictable, and progressive neurological disease. Tertiary dysfunction represents the psychological fallout of chronic illness, encompassing:

• Body Image and Self-Attractiveness: Diminished perception of personal desirability resulting from visible disability, assistive devices, weight fluctuations, or medicalization of the body.
• Sexual Confidence and Efficacy: Generalized loss of confidence regarding sexual performance and competence.
• Fear of Rejection: Anticipatory anxiety regarding partner abandonment, revulsion, or perceived inadequacy due to MS symptoms.
• Performance and Partner Anxiety: Chronic worry regarding whether one can satisfy their partner sexually despite bodily limitations.
• Relational Role Alteration: Disruption of reciprocal intimate partnerships, particularly when a romantic partner adopts informal caregiving duties (e.g., assistance with bathing, catheterization, or mobility), shifting relationship dynamics from romantic parity to caregiver-patient dependence.

6. Theoretical Framework

The foundational architecture of the MSISQ-15 is grounded in the conceptual model of chronic illness sexual impairment first articulated by Frederick W. Foley, PhD and colleagues (Foley et al., 2001; Sanders et al., 2000). Foley synthesized neuro-urological principles with George Engel’s Biopsychosocial Model, establishing that chronic neurodegenerative conditions impact sexual functioning through three distinct tiers: primary, secondary, and tertiary impairment.

Historically, medical models conceptualized sexual dysfunction predominantly through biological reductionism, viewing sexual problems in neurological cohorts as mechanical disruptions of vascular or reflex arcs. Conversely, early psychoanalytic and purely psychological models attributed sexual difficulties in chronically ill individuals almost exclusively to neurotic inhibition, secondary gain, or reactive depression. Foley’s tripartite framework reconciled these divergent paradigms into a coherent, interactive system:

1. The Neurological Foundation (Primary Axis): Grounded in clinical neuro-anatomy, this axis acknowledges that the human sexual response cycle relies upon neurochemical signaling across cholinergic, adrenergic, nitrergic, and dopaminergic systems within the central and peripheral nervous systems. Demyelinating plaques in multiple sclerosis disrupt these signals directly, altering sensation and genital vascular dynamics.
2. The Somatic Burden Axis (Secondary Axis): Derived from functional disability and rehabilitation theories, this component recognizes that human sexuality is bodily and kinetic. Any chronic disease process that compromises biomechanical capability—such as muscle spasticity, central fatigue, and sphincter dysfunction—creates barriers that disrupt intimate activity.
3. The Psychosocial-Relational Axis (Tertiary Axis): Drawing upon cognitive-behavioral theory, social psychology, and systems theory, this dimension posits that illness alters the cognitive appraisals an individual holds regarding their bodily worth. Patients experience cognitive distortions concerning their desirability, social comparison threats, and role strain within their dyadic partnership.

A central premise of this theoretical model is bidirectional interactivity: primary neurological deficits frequently exacerbate tertiary anxieties, while secondary bodily fatigue or incontinence may trigger primary autonomic withdrawal via sympathetic stress activation. By isolating these three tiers, the MSISQ-15 operationalizes this biopsychosocial theory, providing a framework to assess, research, and address each component clinically.

7. Validity

Construct, convergent, and discriminant validity of the MSISQ-15 have been examined across international validation programs, with particular rigor demonstrated in the Spanish validation study conducted by Esteve-Ríos and colleagues (2023) alongside foundational North American and European trials.

Construct and Factorial Validity

Construct validity was demonstrated via structural equation modeling. Confirmatory factor analysis (CFA) substantiated that the theoretical tripartite model represents an optimal fit for empirical observation. Standardized factor loadings across all items were strong, statistically significant (p < 0.001), and mapped consistently onto their designated primary, secondary, and tertiary latent dimensions.

Convergent Validity

Convergent validity was evaluated by correlating MSISQ-15 dimension scores with established gender-specific sexual function inventories. When contrasted against the Male Sexual Function (FSH) questionnaire and the Female Sexual Function-2 (FSM-2) questionnaire, the MSISQ-15 yielded substantial, statistically significant negative correlations:

• MSISQ-15 Total vs. Male Sexual Function (FSH): r = -0.52 (p < 0.001)
• MSISQ-15 Total vs. Female Sexual Function-2 (FSM-2): r = -0.55 (p < 0.001)

These negative correlation coefficients reflect expected scoring directions: higher scores on the MSISQ-15 represent greater sexual dysfunction and symptomatology, whereas higher scores on the FSH and FSM-2 signify superior, healthier sexual functioning. Convergent correlations were strongest within the Primary Causes subscale, confirming that items targeting genital numbness, lubrication deficits, erectile difficulties, and anorgasmia accurately reflect physiological sexual impairment.

Convergent validity was further demonstrated through comparison with health-related quality of life instruments. The MSISQ-15 demonstrated a moderate inverse correlation (r = -0.39, p < 0.001) with the Multiple Sclerosis International Quality of Life Questionnaire (MusiQoL). Higher levels of intimacy impairment were systematically associated with diminished global quality of life, affirming the functional impact of sexual well-being on overall chronic illness adjustment.

Discriminant (Divergent) Validity

Discriminant validity was verified through comparison with relationship satisfaction indices, specifically the Dyadic Adjustment Scale-13 (EAD-13 / DAS-13). Counter to initial intuitive assumptions, empirical analyses demonstrated a non-significant, near-zero correlation between MSISQ-15 scores and global dyadic adjustment (r = -0.08 to -0.12, p > 0.05). This psychometric divergence highlights an important clinical distinction: the presence of multiple sclerosis-related sexual dysfunction does not automatically produce relationship dissatisfaction. Dyads frequently mobilize adaptive coping mechanisms, emotional intimacy, and partner support, enabling marital stability and high relationship satisfaction to persist alongside substantial neurogenic sexual impairment.

8. Reliability

The reliability of the MSISQ-15 has been demonstrated across multiple psychometric investigations. In ordinal scale adaptations, researchers have placed particular emphasis on computing ordinal alpha and composite reliability coefficients, which provide unbiased estimates for categorical Likert distributions compared to traditional Pearson-based Cronbach’s alpha values.

Internal Consistency

In the seminal cross-cultural validation study by Esteve-Ríos et al. (2023) involving 208 MS patients, the instrument demonstrated high internal consistency across the total scale and its subscales:

• Total MSISQ-15 Scale: Ordinal α = 0.89 (exceeding standard criteria for clinical and research instrumentation)
• Primary Causes Subscale: Ordinal α = 0.85
• Secondary Causes Subscale: Ordinal α = 0.81
• Tertiary Causes Subscale: Ordinal α = 0.87

These values align with the original American validation study conducted by Foley et al. (2013), in which Cronbach’s alpha values for the subscales ranged between 0.80 and 0.88 across a cohort of over 1,000 individuals with MS. Item-total correlations across validation studies consistently exceed the conventional psychometric threshold of 0.40, with individual item-rest coefficients ranging from 0.46 to 0.74, indicating that each item contributes reliably to its parent domain without excessive collinear redundancy.

Test-Retest Reliability

Temporal stability evaluated across 2-to-4-week testing intervals under stable neurological conditions has demonstrated high reproducibility. Intraclass Correlation Coefficients (ICC) reported across various European cohorts (e.g., Dutch, Italian, and Polish adaptations) demonstrate stability ranging from ICC = 0.84 to ICC = 0.92, indicating that the instrument captures stable underlying constructs rather than transient daily fluctuations, while retaining sensitivity to longitudinal disease progression and therapeutic intervention.

9. Factor Analysis

The structural dimensionality of the MSISQ-15 has been examined through both exploratory and confirmatory factor analytic frameworks. During the instrument’s initial abbreviation from the original 19-item questionnaire (MSISQ-19), four items exhibiting cross-loadings, weak factor specificity, or low conceptual relevance were systematically removed under exploratory factor analysis, resulting in a balanced 15-item instrument with three 5-item factors.

Confirmatory Factor Analysis (CFA) Methodology

Because the MSISQ-15 items utilize an ordinal 5-point response format, conventional Maximum Likelihood (ML) estimation can distort parameter estimates and deflate standard errors. Modern validation studies, including Esteve-Ríos et al. (2023), employ Weighted Least Squares Mean and Variance adjusted (WLSMV) estimation applied to polychoric correlation matrices, which provides robust parameter estimation for categorical indicators.

Model Fit Parameters

CFA examining the theoretical three-factor correlated model (Primary, Secondary, and Tertiary Causes) has yielded strong goodness-of-fit indices across published cohorts:

• Comparative Fit Index (CFI): 0.970 (surpassing the stringent ≥ 0.95 benchmark for superior model fit)
• Tucker-Lewis Index (TLI): 0.960 (exceeding the standard ≥ 0.95 threshold)
• Root Mean Square Error of Approximation (RMSEA): 0.070 (95% Confidence Interval: [0.052, 0.082]), indicating an acceptable and stable error of approximation in multidimensional modeling.
• Chi-Square / Degrees of Freedom (χ²/df): Well within the recommended < 2.5 acceptable threshold for structural models.

Factor Loadings and Latent Intercorrelations

Standardized factor loadings (λ) across all 15 items demonstrate high salience:

• Primary Subscale Items: Loadings range from λ = 0.68 to λ = 0.86, loading strongly onto direct neurogenic parameters.
• Secondary Subscale Items: Loadings range from λ = 0.59 to λ = 0.78, capturing physical and symptomatic limitations.
• Tertiary Subscale Items: Loadings range from λ = 0.72 to λ = 0.89, reflecting psychosocial, emotional, and partner-related anxieties.

Correlations between the three latent factors are moderate (ranging from r = 0.45 to r = 0.62), demonstrating that while the dimensions are related aspects of the overarching construct of MS-related sexual dysfunction, they maintain empirical distinctiveness, supporting the retention of separate subscale scores alongside the global total score.

10. Instrument / Measurement Tool

The technical parameters and administrative specifications of the MSISQ-15 are detailed below:

• Instrument Name: Multiple Sclerosis Intimacy and Sexuality Questionnaire-15 (MSISQ-15)
• Test Type: Patient-Reported Outcome Measure (PROM); standardized psychological self-report questionnaire
• Administration Format: Paper-and-pencil questionnaire or secure digital/web-based administration
• Target Clinical Population: Adult clinical patients (age 18+) diagnosed with Multiple Sclerosis (clinically isolated syndrome, relapsing-remitting, secondary progressive, or primary progressive courses) or related spinal cord pathology
• Number of Items: 15 items
• Subscale Distribution:
  • Primary Sexual Dysfunction Subscale: 5 items (Items 1, 2, 3, 4, 5)
  • Secondary Sexual Dysfunction Subscale: 5 items (Items 6, 7, 8, 9, 10)
  • Tertiary Sexual Dysfunction Subscale: 5 items (Items 11, 12, 13, 14, 15)
• Response Scale: 15 items scored on a 5-point Likert-type scale from 1 to 5 (1 = Never, 2 = Once in a while, 3 = Sometimes, 4 = Fairly often, 5 = Always).
• Scoring Algorithm:
  • All 15 items are positively scored without reverse-keyed items.
  • Individual subscale scores are obtained by summing the 5 designated items within each respective domain (subscale range: 5 to 25).
  • The global MSISQ-15 total score is calculated by summing all 15 items (total range: 15 to 75).
  • Higher numerical scores reflect greater severity of sexual dysfunction, greater physiological impediment, and higher psychosocial distress.
• Completion Time: Approximately 3 to 5 minutes, minimizing patient fatigue.

11. Permissions & Fee and Test Year

The 15-item revision of the Multiple Sclerosis Intimacy and Sexuality Questionnaire was published in 2013 by Dr. Frederick W. Foley and colleagues. The comprehensive Spanish cross-cultural adaptation and structural validation study was published in 2023 by Antonio Esteve-Ríos, María José Cabañero-Martínez, Silvia Escribano, Frederick Foley, and Sofía García-Sanjuán.

Licensing and Clinical Usage Permissions: The MSISQ-15 is generally available for clinical practice and non-commercial academic research. While the published validation studies (such as the Esteve-Ríos et al., 2023 open-access publication in PeerJ) outline its psychometric properties and structural framework, researchers and clinicians intending to implement the MSISQ-15 in official trials, institutional registries, or commercial interventions should obtain appropriate administrative permissions from the scale developer (Dr. Frederick Foley) or the authors of the respective language adaptation. The tool is typically distributed free of royalty fees for non-profit and academic research endeavors, consistent with clinical research standards for neuro-rehabilitation outcome measures.

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13. Items of the Scale