High rate of dyspareunia and probable vulvodynia in Ehlers-Danlos syndromes and hypermobility spectrum disorders: An online survey.

Vulvodynia is debilitating vulvar pain accompanied by dyspareunia (pain with sexual intercourse). Ehlers-Danlos syndromes (EDS) and hypermobility spectrum disorders (HSD) may represent a predisposing factor for vulvodynia given a high rate of dyspareunia in these conditions. We conducted an online survey of women with EDS or HSD to assess rates of dyspareunia and estimate rates of vulvodynia, report rates of comorbid conditions common to EDS or HSD and vulvodynia, and examine rates of conditions contributing to dyspareunia in women with EDS or HSD. Women with EDS or HSD (N = 1,146) recruited via social media were 38.2 ± 11.5 years old, primarily White (94.4%), and resided in the United States (78.5%). 63.7% of participants reported dyspareunia and 50% screened positive for vulvodynia. The rate of comorbid conditions common to EDS or HSD and vulvodynia were: irritable bowel syndrome, 6.5%; fibromyalgia, 40.0%; temporomandibular joint dysfunction, 56.4%; migraine, 6.7%; interstitial cystitis, 1.7%; and mast cell activation syndrome, 10.2%. Participants reporting dyspareunia also reported ovarian cysts, fibroids, or abdominal or pelvic scars, 47.5%; endometriosis, 26.5%; and genital lacerations, 19.3%. Women with EDS or HSD may have a higher rate of vulvodynia (50.0%) than women in the U.S. population at large (8%) and should be assessed for dyspareunia and vulvodynia.

Double-blinding of an acupuncture randomized controlled trial optimized with clinical translational science award resources.

BACKGROUND: Clinical trial articles often lack detailed descriptions of the methods used to randomize participants, conceal allocation, and blind subjects and investigators to group assignment. We describe our systematic approach to implement and measure blinding success in a double-blind phase 2 randomized controlled trial testing the efficacy of acupuncture for the treatment of vulvodynia. METHODS: Randomization stratified by vulvodynia subtype is managed by Research Electronic Data Capture software's randomization module adapted to achieve complete masking of group allocation. Subject and acupuncturist blinding assessments are conducted multiple times to identify possible correlates of unblinding. RESULTS: At present, 48 subjects have been randomized and completed the protocol resulting in 87 subject and 206 acupuncturist blinding assessments. DISCUSSION: Our approach to blinding and blinding assessment has the potential to improve our understanding of unblinding over time in the presence of possible clinical improvement.

Vulvodynia, "A Really Great Torturer": A Mixed Methods Pilot Study Examining Pain Experiences and Drug/Non-drug Pain Relief Strategies.

BACKGROUND: Women with vulvodynia, a chronic pain condition, experience vulvar pain and dyspareunia. Few studies examine the range and combination of treatment strategies that women are actually using to reduce vulvodynia. AIM: To describe pain experiences and pain relief strategies of women with vulvodynia. METHODS: Convenience sample, 60 women with vulvodynia (median age 32.5 [interquartile range {IQR} 8.5] years; 50 white, 10 racial/ethnic minorities) completed PAINReportIt and reported use of drugs and alcohol and responded to open-ended questions. Univariate descriptive statistics and bivariate inferential tests were used to describe average pain intensity scores, alcohol use, smoking, number of pain relief strategies, and their associations. Women's open-ended responses about their pain experiences and drug and non-drug pain relief strategies (NDPRS) were analyzed for patterns. OUTCOMES: Our mixed methods analysis connected data from pain measures, prescribed treatments and self-reported behaviors with women's free responses. This enabled nuanced insights into women's vulvodynia pain experiences. RESULTS: Women's descriptions of their pain and suffering aligned with their reported severe pain and attempts to control their pain, with a median pain intensity of 6.7 (IQR 2.0) despite use of adjuvant drugs (median 2.0 [IQR 2.0]), and opioids (median 1.0 [IQR 2.0]). 36 women (60%) used alcohol to lessen their pain. 26 women (43%) listed combining analgesics and alcohol to relieve their pain. 30 women (50%) smoked cigarettes. 54 women (90%) used ≥1 NDPRS. The mean number of NDPRS used was 2.1 ± 1.3 (range 0-6). The 5 most common NDPRS from women's comments were herbal medicine (40%), acupuncture (27%), massage (22%), hypnosis (15%), and mental healthcare (13%). CLINICAL IMPLICATIONS: Severe pain in women with vulvodynia may be a clinical indicator of those at higher risk of combining prescription pain medications with alcohol, which are all central nervous system depressants and may potentiate overdose. STRENGTHS AND LIMITATIONS: This pilot study demonstrated that the mixed methods approach to help understand the complexity of vulvodynia was feasible. We identified data showing a reliance on a high-risk mix of prescriptions and alcohol to reduce vulvodynia pain and a high prevalence of cigarette smoking. However, as a pilot study, these results are considered preliminary; the sample may not be representative. Perhaps only women at the extreme end of the pain continuum participated, or women took the survey twice because identifiers were not collected. CONCLUSION: Despite attempts to reduce pain using multiple therapies, including alcohol, women's vulvodynia pain is severe and not controlled. Schlaeger JM, Pauls HA, Powell-Roach KL, et al. Vulvodynia, "A Really Great Torturer": A Mixed Methods Pilot Study Examining Pain Experiences and Drug/Non-drug Pain Relief Strategies. J Sex Med 2019;16:1255-1263.

Identifying distinct nanoscopic features of native collagen fibrils towards early diagnosis of pelvic organ prolapse.

Pelvic organ prolapse (POP) is characterized by weakening of the connective tissues and loss of support for the pelvic organs. Collagen is the predominant, load-bearing protein within pelvic floor connective tissues. In this study, we examined the nanoscopic structures and biomechanics of native collagen fibrils in surgical, vaginal wall connective tissues from healthy women and POP patients. Compared to controls, collagen fibrils in POP samples were bulkier, more uneven in width and stiffer with aberrant D-period. Additionally, the ratio of collagen I (COLI) and collagen III (COLIII) is doubled in POP with a concomitant reduction of the amount of total collagen. Thus, POP is characterized by abnormal biochemical composition and biophysical characteristics of collagen fibrils that form a loose and fragile fiber network accountable for the weak load-bearing capability. The study identifies nanoscale alterations in collagen as diagnostic markers that could enable pre-symptomatic or early diagnosis of POP. FROM THE CLINICAL EDITOR: Pelvic organ prolapse (POP) occurs due to abnormalities of the supporting connective tissues. The underlying alterations of collagen fibers in the connective tissues have not been studied extensively. In this article, the authors showed that collagen fibrils in POP patients were much different from normal controls. The findings may provide a framework for the diagnosis of other connective diseases.

Lack of Diversity in Research on Females with Ehlers-Danlos Syndromes: Recruitment Protocol for a Quantitative Online Survey.

BACKGROUND: Ehlers-Danlos syndromes (EDS) are a group of connective tissue disorders caused by fragile lax collagen. Current EDS research lacks racial and ethnic diversity. The lack of diversity may be associated with the complexities of conducting a large international study on an underdiagnosed condition and a lack of EDS health care providers who diagnose and conduct research outside of the United States and Europe. Social media may be the key to recruiting a large diverse EDS sample. However, studies that have used social media to recruit have not been able to recruit diverse samples. OBJECTIVE: This study aims to discuss challenges, strategies, outcomes, and lessons learned from using social media to recruit a large sample of females with EDS. METHODS: Recruitment on social media for a cross-sectional survey examining dyspareunia (painful sexual intercourse) in females was examined. Inclusion criteria were (1) older than 18 years of age, (2) assigned female at birth, and (3) diagnosed with EDS. Recruitment took place on Facebook and Twitter (now X), from June 1 to June 25, 2019. RESULTS: A total of 1178 females with EDS were recruited from Facebook (n=1174) and X (n=4). On Facebook, participants were recruited via support groups. A total of 166 EDS support groups were identified, 104 permitted the principal investigator to join, 90 approved posting, and the survey was posted in 54 groups. Among them, 30 of the support groups posted in were globally focused and not tied to any specific country or region, 21 were for people in the United States, and 3 were for people outside of the United States. Recruitment materials were posted on X with the hashtag #EDS. A total of 1599 people accessed the survey and 1178 people were eligible and consented. The average age of participants was 38.6 (SD 11.7) years. Participants were predominantly White (n=1063, 93%) and non-Hispanic (n=1046, 92%). Participants were recruited from 29 countries, with 900 (79%) from the United States and 124 (11%) from Great Britain. CONCLUSIONS: Our recruitment method was successful at recruiting a large sample. The sample was predominantly White and from North America and Europe. More research needs to be conducted on how to recruit a diverse sample. Areas to investigate may include connecting with more support groups from outside the United States and Europe, researching which platforms are popular in different countries, and translating study materials into different languages. A larger obstacle to recruiting diverse samples may be the lack of health care providers that diagnose EDS outside the United States and Europe, making the pool of potential participants small. There needs to be more health care providers that diagnose and treat EDS in countries that are predominantly made up of people of color as well as research that specifically focuses on these populations. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): RR1-10.2196/53646.

Telehealth in a Pelvic Floor Physical Therapy Clinic: A Retrospective Cohort Study.

IMPORTANCE: Telehealth offers advantages to patients with pelvic floor disorders because they face unique barriers to care; however, attendance of telehealth appointments is unknown. OBJECTIVE: The objective of this study was to examine the attendance of telehealth appointments in urogynecology patients receiving pelvic floor physical therapy as compared with in-person visits before and during the COVID-19 pandemic. STUDY DESIGN: We retrospectively collected electronic medical record data from patients engaging in pelvic floor physical therapy from 2019, and pre- and post-COVID-19 in 2020. Information included appointment type, attendance, age, primary diagnoses, insurance status, and zip code. Cohort differences were examined using the χ2 test and analyses of variance. RESULTS: Our sample included 359 individuals scheduled for in-person visits in 2019, 57 for telehealth visits in 2020, and 283 for in-person visits in 2020. Patients scheduled for telehealth appointments were younger (39 ± 13 years) than patients in 2019 (45 ± 14 years) or 2020 (42 ± 14 years) in-person cohorts (χ2 (2, 696) = 6.8, P < 0.001). Patients attended telehealth appointments at higher rates (73.7%) than in-person visits in 2019 (56.8%) and 2020 (45.6%; χ2 (2, 699) = 26.2, P < 0.001). Attendance did not differ across primary diagnoses. Proximity based on zip code was not associated with attendance. CONCLUSIONS: Pelvic floor physical therapy attendance rates were highest for patients with telehealth visits as compared with in-person visits. Our findings encourage health care providers to continue or begin to offer telehealth visits for pelvic floor physical therapy for the urogynecology patient population.

Evaluation and Treatment of Vulvodynia: State of the Science.

Vulvodynia affects 7% of American women, yet clinicians often lack awareness of its presentation. It is underdiagnosed and often misdiagnosed as vaginitis. The etiology of vulvodynia remains unknown, making it difficult to identify or develop effective treatment methods. The purpose of this article is to (1) review the presentation and evaluation of vulvodynia, (2) review the research on vulvodynia treatments, and (3) aid the clinician in the selection of vulvodynia treatment methods. The level of evidence to support vulvodynia treatment varies from case series to randomized controlled trials (RCTs). Oral desipramine with 5% lidocaine cream, intravaginal diazepam tablets with intravaginal transcutaneous electric nerve stimulation (TENS), botulinum toxin type A 50 units, enoxaparin sodium subcutaneous injections, intravaginal TENS (as a single therapy), multimodal physical therapy, overnight 5% lidocaine ointment, and acupuncture had the highest level of evidence with at least one RCT or comparative effectiveness trial. Pre to posttest reduction in vulvar pain and/or dyspareunia in non-RCT studies included studies of gabapentin cream, amitriptyline cream, amitriptyline with baclofen cream, up to 6 weeks' oral itraconazole therapy, multimodal physical therapy, vaginal dilators, electromyography biofeedback, hypnotherapy, cognitive behavioral therapy, cold knife vestibulectomy, and laser therapy. There is a lack of rigorous RCTs with large sample sizes for the treatment of vulvodynia, rendering it difficult to determine efficacy of most treatment methods. Clinicians will be guided in the selection of best treatments for vulvodynia that have the highest level of evidence and are least invasive.

Women's Experience of Living with Vulvodynia Pain: Why They Participated in a Randomized Controlled Trial of Acupuncture.

Introduction: Vulvodynia is vulvar pain lasting at least 3-months without clear identifiable cause that may have other associated factors. The aim, to explore motivations of women participating in a double-blind randomized controlled trial of acupuncture for vulvodynia. Methods: Responses to the question: "Tell me about why you decided to participate in this study" were analyzed using conceptual content analysis to identify patterns in motivation for study participation. Results: Four patterns emerged: 1) desire to address uncontrolled pain, 2) desire for understanding, 3) wish to contribute to knowledge generation, and 4) need to remove cost barriers. Conclusion: Motivations indicate vulvodynia-specific aspects of acceptability of acupuncture. Clinical Trial Registration: NCT03364127.

Image-based documentation of vulvodynia pain location.

Aims: Better documentation of vulvar pain is needed. We examined pain locations marked on general body and genital specific outlines among women with vulvodynia. Methods: 62 women (mean age 32.1 ± 9.5 years) with vulvodynia marked their pain on a digital genital specific outline (22 segments) and 59 of those women also marked their pain on a digital general body outline (48 segments). We used ImageJ software to determine body surface area (BSA) for each outline. Results: On the general body outline, 24/48 segments were marked; 22/22 segments were marked on the genital specific outline. There was a moderate correlation (r = 0.43; p = 0.001) between the BSA marked on the general body outline and the BSA marked on the genital area outline. Conclusions: Findings support concurrent validity of the BSA as a measure of pain location using either outline.

Women with genital pain need to be able to show their healthcare provider where they have pain, and providers need to document where women have pain. In total, 62 women with vulvodynia used a computer tablet to mark their pain on a general body outline and a genital specific outline. We used computer software to document the location of women's pain looking at percent body surface area. Women marked half of the segments on the general body outline and all the segments on the genital specific outline. Because women marked almost the same percent of body surface area on the general body outline as they did on the genital specific outline, percent body surface may be used to measure pain location.

Protocol for double-blind RCT of acupuncture for vulvodynia.

Background: Vulvodynia, vulvar pain of unknown origin lasting at least 3 months, affects 7% of American women. Dyspareunia, its frequent companion, renders sexual intercourse virtually impossible. Although few therapies are efficacious and rapid pain relief is rarely possible, there have been no sham/placebo-controlled studies of acupuncture for vulvodynia. Aims are to: 1) determine efficacy of acupuncture for vulvodynia, 2) explore duration of the acupuncture effect. Methods: In a pretest/posttest randomized controlled, double-blind (practitioner-patient) efficacy trial of a standardized acupuncture protocol, we will randomize 80 participants 1:1 to either penetrating needle or skin-touch placebo needle groups. Both types of needles are designed to blind both the acupuncturist and participant. Participants with vulvodynia will insert and remove a tampon as a standardized stimulus and complete primary measures of vulvar pain (pain intensity) and secondary measures of dyspareunia (Female Sexual Function Index, FSFI dyspareunia subscale score) and sexual function (FSFI total score) pretreatment, after the 10th acupuncture session, and pain measures weekly until return to pretest levels. Upon study completion control group participants will be offered 10 free real acupuncture sessions. Discussion: This is the first multi-needle multi-session RCT using double-blind acupuncture needles as a reliable sham. We hypothesize that controlling for baseline, at posttest there will be statistically significant less vulvar pain and dyspareunia and more sexual function over five weeks in the penetrating needle group compared to the skin touch placebo group. Conclusion: This study is responsive to the need for efficacious pain management for women with vulvodynia.ClinicalTrials.gov Identifier: NCT03364127.

A Systematic Review of Intravaginal Diazepam for the Treatment of Pelvic Floor Hypertonic Disorder.

This systematic review evaluates the efficacy of intravaginal diazepam in treating chronic pelvic pain and sexual dysfunction associated with high-tone pelvic floor dysfunction. A literature search was conducted in Medline and Web of Science, including articles from the database's inception to July 2019. The search identified 126 articles, and 5 articles met study inclusion criteria: 2 observational reviews and 3 small randomized, controlled trials (RCTs) evaluating intravaginal diazepam for high-tone pelvic floor dysfunction. The 2 observational studies identified subjective reports of improvement in sexual function for a majority of women, 96% and 71%, in each study. However, there were no statistical differences between Female Sexual Function Index (FSFI) and Visual Analog Scale (VAS) scores for pain identified. One RCT found no significant changes between groups in median FSFI or VAS scores, and a second RCT found no significant changes between groups in 100-mm VAS scores. The third RCT demonstrated that compared with placebo, treatment with transcutaneous electrical nerve stimulation and intravaginal diazepam for women with vestibulodynia and high-tone pelvic floor dysfunction yielded significant differences in reduction of dyspareunia (P ≤ .05), ability to relax pelvic floor muscles after contraction (P ≤.05), and current perception threshold values at a 5-Hz stimulation related to C fibers (P < .05), but no significant changes in 10-cm VAS scores. Intravaginal diazepam may be helpful in women with a specific diagnosis of high-tone pelvic floor dysfunction, but more and larger studies are needed to confirm these potential effects.

Sensory pain characteristics of vulvodynia and their association with nociceptive and neuropathic pain: an online survey pilot study.

OBJECTIVES: To evaluate self-reported sensory pain scores of women with generalized vulvodynia (GV) and provoked vestibulodynia (PVD), characterize pain phenotypes, and assess feasibility of using the Internet for recruitment and data collection among women with vulvodynia. METHODS: Descriptive online survey. Data collected using an online survey accessed via a link on the National Vulvodynia Association web site. Convenience sample, 60 women aged 18 to 45 years (mean = 32.7 ± 5.5); 50 white, 2 black/African American, 4 Hispanic/Latino, and 4 Native American/Alaskan Native, diagnosed with vulvodynia, not in menopause. Pain assessment and medication modules from PAINReportlt. RESULTS: Women with GV (n = 35) compared to PVD (n = 25). Estimated mean pain sites (2.5 ± 1.4 vs 2.2 ± 1.0, P = 0.31), mean current pain (8.7 ± 1.4 vs 5.5 ± 4.0, P = 0.0008), worst pain (8.1 ± 1.8 vs 6.1 ± 3.6, P = 0.02), and least pain in the past 24 hours (4.4 ± 1.8 vs 2.0 ± 2.0, P < 0.0001). Average pain intensity (7.1 ± 1.2 vs 4.6 ± 2.9, P = 0.0003) on a scale of 0 to 10, mean number of neuropathic words (8.3 ± 3.6 vs 7.7 ± 5.0), and mean number of nociceptive words (6.9 ± 4 vs 7.5 ± 4.4). Nineteen (54%) women with GV compared to 9 (38%) with PVD were not satisfied with pain levels. CONCLUSION: Women with GV reported severe pain, whereas those with PVD reported moderate to severe pain. Pain quality descriptors may aid a clinician's decisions about whether to prescribe adjuvant drugs vs opioids to women with vulvodynia.

Expression of lysyl oxidase and transforming growth factor beta2 in women with severe pelvic organ prolapse.

OBJECTIVE: To determine the mRNA expression of lysyl oxidase (LOX) and transforming growth factor beta2 (TGF beta2) in subjects with advanced pelvic organ prolapse as compared to asymptomatic controls. STUDY DESIGN: Seventeen women undergoing vaginal hysterectomy were recruited for the study. Nine women with grade > or = 3 pelvic organ prolapse by the Baden-Walker grading scale were recruited. Eight subjects without pelvic organ prolapse or urinary incontinence undergoing hysterectomy for other indications were recruited as asymptomatic controls. A 1-cm portion of the bilateral distal uterosacral ligaments was excised and immediately frozen at -80 degrees C. Total RNA was extracted, quantified and subjected to reverse transcription for cDNA synthesis. beta-Actin was used as the reference for the semiquantitative analysis. Known volumes of the polymerase chain reaction (PCR) products for each reaction were electrophoresed in agarose gels stained with ethidium bromide and photographed with a digital camera. The optical density for each sample was measured by using computerized image analysis software. The relative abundance of each specific message was calculated as the ratio of PCR product for LOX or TGF beta2 divided by the amount of PCR product for beta-actin from the same sample. RESULTS: The mean age of the study subjects was 55.7 years (38-67) versus 47.1 for the controls (44-54). Mean parity was 4.4 for the study subjects and 2.7 for the controls. Seventy-eight percent of the study subjects were postmenopausal, and 14% of the controls postmenopausal. All postmenopausal subjects had at least 1 month of estrogen therapy prior to surgery. The mean LOX/beta-actin ratio for the study group was 0.35 as compared to 0.72 for the control group. This was statistically significant with a p value of 0.049. The mean TGF beta2/beta-actin ratio for the study group was 0.12 as compared to 0.20 for the control group. This was not statistically significant (p = 0.46). CONCLUSION: Patients with severe pelvic organ prolapse (grade > or = 3) have a significant reduction in the mRNA expression of lysyl oxidase as compared to asymptomatic controls. The mRNA expression of TGF beta2 was not statistically different between the 2 groups. These findings lend further credence to the concept of specific biochemical changes in the pelvic floor in women with pelvic organ prolapse.

Validation of a Spanish version of the Pelvic Organ Prolapse Incontinence Sexual Questionnaire.

OBJECTIVE: To develop a validated Spanish version of the Pelvic Organ Prolapse Incontinence Sexual Questionnaire (PISQ). METHODS: The PISQ is a previously described validated and reliable questionnaire. We used a back-translation method to develop a Spanish-language version. Twenty-six bilingual patients with pelvic organ prolapse and/or urinary incontinence were randomized to complete either the original English version or the final Spanish version of the PISQ first, followed by the other questionnaire. Scores of the two versions were compared. Paired t test for total PISQ and its three domain scores and Wilcoxon signed rank test for each item assessed the bias between the two equivalent versions. Agreement between the two versions was assessed by weighted kappa statistics, with 95% confidence intervals for each item. P values of .05 or less were considered significant, and kappa values of .75 or greater were considered to indicate good agreement. RESULTS: English and Spanish versions demonstrated no differences for each of the factors and total scores (P = .15, .83, .28, and .56, respectively). Wilcoxon signed rank test demonstrated that one item was answered differently in the English and Spanish versions. Good agreement between Spanish and English versions in 30 of the 31 items was demonstrated by weighted kappa statistics. Overall, 72% of women scored both versions of the questionnaire equivalently. CONCLUSIONS: We have developed a validated and reliable Spanish questionnaire to evaluate sexual functioning in Spanish-speaking patients with pelvic organ prolapse and/or urinary incontinence.

Structural and mechanical profiles of native collagen fibers in vaginal wall connective tissues.

Collagen, an ubiquitous biomaterial, confers robustness and resilience to connective tissues. In this study, we analyzed the structure and elasticity profile of collagen from the vaginal wall connective tissue of healthy pre-menopausal (pre-M) and postmenopausal (post-M) women. The histological staining assisted study with an atomic force microscope renders the examination of native collagen fibers on site of the connective tissue from nanoscopic scale to microscopic scale with high spatial resolution. Our results suggest that during menopause, collagen's structure and elasticity are subject to changes at all levels of organization- between individual collagen fibers, between collagen and muscle, and between collagen and other matrix elements. The systematic analysis of the native structure and mechanical properties of collagen within a tissue provides a potential way to study non-fatal conditions such as pelvic organ prolapse and other genito-urinary disorders, where the initial symptoms are subtle and multivariate, and where early detection of patient's condition may allow better non-invasive interventions and reduce the number of women undergoing surgical correction of these common disorders.

Validation of Spanish versions of the Pelvic Floor Distress Inventory (PFDI) and Pelvic Floor Impact Questionnaire (PFIQ): a multicenter validation randomized study.

INTRODUCTION AND HYPOTHESIS: The purpose of this study is to validate Spanish versions of the Pelvic Floor Distress Inventory (PFDI) and Pelvic Floor Impact Questionnaire (PFIQ). METHODS: Spanish versions were developed using back translation and validation was performed by randomizing bilingual women to complete the Spanish or English versions of the questionnaires first. Weighted kappa statistics assessed agreement for individual questions; interclass correlation coefficients (ICC) compared primary and subscale scores. Cronbach's alpha assessed internal consistency of Spanish versions. To detect a 2.7 point difference in scores with 80% power and alpha of 0.05, 44 bilingual subjects were required. RESULTS: Individual questions showed good to excellent agreement (kappa > 0.6) for all but eight questions on the PFIQ. ICCs of primary and subscale scores for both questionnaires showed excellent agreement. (All ICC > 0.79). All Cronbach's alpha values were excellent (>0.84) for the primary scales of both questionnaires. CONCLUSIONS: Valid and reliable Spanish versions of the PFIQ and PFDI have been developed.