Developing the initial raw scale
Existing standardized scales were analysed with a particular focus on health related quality of life items associated with sexual dysfunction in both men and women. Scales reviewed were:
- Menopause Rating Scale (MRS) 2
- Aging Males’ Symptoms Scale (AMS) 13
- Female Sexual Function Index (FSFI)4
- Derogatis Interview for Sexual Functioning (DISF) 56
- Female Sexual Distress Scale (FSDS) 7
- Brief Sexual Function Questionnaire (BSFQ) for men 8
Altogether 40 specific items and eight general questions were selected covering the dimensions of well-being & satisfaction with life (psychological and somatic aspects), urogenital & sexual complaints, sexual desire (libido), sexual arousal or responsiveness to sexual stimulation, sexual activity and satisfaction from own perspective and perceived partner’s view. In addition information on socio-demographic variables, partnership, importance of sexuality, and number of sexual events in the last month were selected.
Choice of data collection
The scale was designed as paper-based, self-administrable patient reported outcome questionnaire. There is no evidence available yet how electronic or web-based administration would influence the results.
Choice of recall period
The goal was the assessment of current sexual function, including the view of the partner, as subjectively perceived by the index person. A one month recall period was selected as it was assumed that the experience gathered in the most recent month would dominate a persons responses.
Response options
A 5-point Likert scale was used to document the response for each question (item). Each item requires the responder to select an item if the symptoms/complaints apply, and if so, how severe/intense or strong they are perceived.
Evaluation of patients understanding
A pilot study of the raw scale undertaken prior to the normative sample survey. 20 people (10 men, 10 women) were included. Responses were used to revise the raw scale.
Selection of final items and scale format
The format of the final scale was developed in a population-based normative sample survey. Selection of items was based on a series of factorial analyses (Principal Component Method with Varimax Rotation) using data from the population-based normative sample survey. Initially the total raw scale was used to analyze the internal structure of the QRS and to understand relationships among specific items.
Items that were not associated with the main factors were eliminated from the final questionnaire unless there was good reason to expect that the study sample chosen was inappropriate to decide upon the importance of certain items, e.g. items that are related to side effects of treatment – which could not be tested in the normative survey. The core scale consists of 32 specific items and 8 complementary questions that may be used, but are not necessary for the integrity of the scale or the evaluation process.
Final identification of items and sub-domains
This basis for scoring was developed around the core goal of a simple instrument that could be used by both clinicians and researchers. All answers received a point. ‘Not applicable/no complaints’ was coded with a score of 1. If ‘yes’ was selected, one of four intensity grades was chosen (score = 2, 3, 5 or 5). Individual item scores were then summed with invidual scores being given to three sub-domains (psycho-somatic quality of life, sexual dysfunction as a self-reflection and sexual dysfunction as perceived by the partner 9.
Usability
From a practical perspective, the QSF scale was well accepted although intimate questions were not always answered completely. Possible reasons for the good performance are the self-administrative nature of the questionnaire, the straight-forward, easily-understood questions and that completion takes <10 minutes. However, responders also noted hesitation, particularly at the beginning, to answer intimate questions. Having said that, most questionnaires were successfully completed and it was rare for the QRS to be rejected by responders due to items being too sensitive or private to complete.
No burden for the administrator of the scale is expected due to its self-explanatory nature. In addition, the scoring and evaluation is very simple and can be done by immediately using a simple “evaluation form”.
1. Daig I, Heinemann LAJ, Kim S et al. The Aging Males Symptoms (AMS) scale: Review of its methodological characteristics. Health and Quality of Life Outcomes 2003;1:77 (December 2003).
2. Heinemann LAJ, Potthoff P, Schneider HPG. International versions of the Menopause Rating Scale (MRS). Health and Quality of Life Outcomes 2003;1:28 (30 July 2003).
3. Heinemann LAJ, Saad F, Zimmermann T et al. The Aging Males Symptoms (AMS) scale: update and compilation of international versions. Health and Quality of Life Outcomes 2003;1:15 (1 May 2003).
4. Rosen R, Brown C, Heiman J et al. The female Sexual Function Index (FSFI): A multidimensional self-report instrument for the assessment of female sexual function. J Sex Mar Ther 2000; 26:191-208.
5. Derogatis LR, Melisanatos N. The DSFI : A multidimensional measure of sexual functioning. J Sex Mar Ther 1979;5:244.
6. Derogatis LR. The Derogates Interview for Sexual Functioning (DISF)/DISF-R): an introductory report. J Sex Mar Ther 1997;23:291-6.
7. Derogates LR, Burnett A, Heiman J, Leiblum S, Rosen R. Development and continuing validation of the Female Sexual Distress Scale (FSDS). Presented at the 4th Annual Female Sexual Function Forum, Boston, MA (October 29,2001).
8. Reynolds III CF, Frank E, Thase ME, Houck PR, Jennings JR, Howell JR, Lilienfeld SO, Kupfer DJ. Assessment of sexual function in depressed, impotent, and healthy men: factor analysis of a Brief Sexual Function Questionnaire (BSFQ) for men. Psych Res 1987;24:231-50.
9. Heinemann LAJ, Potthoff P, Heinemann K, Pauls A, Ahlers CJ, Saad F. Scale for Quality of Sexual Function (QSF) as an outcome measure for both genders? J Sexual Med 2005;2:82-95.
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