Feasibility and Acceptability of a Web-Based Treatment with Telephone Support for Postpartum Women With Anxiety: Randomized Controlled Trial

Background Postpartum anxiety can have adverse effects on the mother and child if left untreated. Time constraints and stigma are common barriers to postpartum treatment. Web-based treatments offer potential flexibility and anonymity. What Am I Worried About (WaWa) is a self-guided treatment based on cognitive-behavioral and mindfulness principles for women experiencing postpartum anxiety. WaWa was developed in Australia and consists of 9 modules with optional weekly telephone support. WaWa was adapted to a Web-based version for use in England (Internet-based What Am I Worried About, iWaWa). Objective This study aimed to investigate the feasibility (engagement and usability) and acceptability (usefulness, satisfaction, and helpfulness) of iWaWa among English postpartum women with anxiety. Methods Postpartum (<12 months) women with mild-to-severe anxiety were recruited anonymously via social media during an 8-week period. Participants were randomized to the iWaWa treatment (8 weeks) or wait-list control group. Treatment and study feasibility and acceptability were assessed after the treatment, and anxiety symptoms were assessed at baseline, 8 weeks postrandomization, and 12 weeks postrandomization (treatment group only) using Web-based questionnaires. Semistructured telephone interviews were carried out after the treatment period for a more in-depth exploration of treatment acceptability and feasibility. Results A total of 89 eligible women were recruited through social media and randomized into the treatment (n=46) or wait-list control group (n=43). Women were predominantly Caucasian, well-educated, married, on maternity leave, first-time mothers and reported moderate levels of anxiety. Dropout rates were high, especially in the treatment group (treatment: 82%, 38/46; wait-list control: 51%, 22/43). A total of 26 women started iWaWa with only 2 women completing all 9 modules. Quantitative and qualitative data suggest iWaWa was experienced as generally useful and helpful. Participants enjoyed iWaWa’s accessibility, anonymity, and weekly reminders, as well as the introduction to the principles of cognitive-behavioral therapy (CBT) and mindfulness. However, iWaWa was also experienced as not user-friendly enough, too long, and not smartphone-friendly. Parts of the content were experienced as not always relevant and appropriate. Participants felt that iWaWa could be improved by having it in a smartphone app format and by making the content more concise and inclusive of different parenting styles. Conclusions Despite interest in iWaWa, the results suggest that both the study and iWaWa were not feasible in the current format. However, this first trial provides useful evidence about treatment format and content preferences that can inform iWaWa’s future development, as well as research and development of Web-based postpartum anxiety treatments, in general, to optimize adherence. Trial Registration ClinicalTrials.gov NCT02434406; https://clinicaltrials.gov/ct2/show/NCT02434406 (Archived by WebCite at http://www.webcitation.org/6xTq7Bwmd)


Postpartum Anxiety
Anxiety disorders such as generalized anxiety disorder, obsessive-compulsive disorder, panic disorder, and phobias in the first year after birth (postpartum) are common with prevalence rates ranging between 9.9% and 20% [1][2][3]. Anxieties in the postpartum period are often life-stage specific, for example, worries about baby's care and health and fear of criticism and inadequacy as a mother [4]. Postpartum anxiety disorders can either be a recurrence of a previous disorder or develop as a first episode. Symptom intensity and associated degree of impairment of these anxiety disorders can vary over the course of the postpartum period [5]. Despite available effective treatments [6][7][8][9][10], postpartum mental health problems often go undetected or untreated [11,12]. Low screening and diagnosis rates play a role, but some women with emotional difficulties postpartum are often more reluctant to disclose and seek help [13][14][15]. Possible reasons for this include being too busy to get around to seeking help and feeling too embarrassed or having no-one they felt comfortable talking to [14], as well as child care concerns [16].
The importance of having efficient and timely treatments is highlighted by the adverse effects of untreated mental health problems on the physical and psychological health of the mother, child, and family [17,18], as well as potential costs to society [11]. For example, it has been shown that maternal anxiety can affect infant bonding and feeding [19,20] and may negatively affect the child's cognitive and social development [17]. Considering the importance of treatment and unique postpartum barriers to accessing treatment, providing convenient and anonymous treatment seems essential.

Web-Based Self-Help Treatments
One approach of offering anonymous and convenient treatment is Web-based self-help treatments, which run on computers, tablets, or smartphones and allow individuals to work through written therapy material without or with minimal therapist or mental health professionals' assistance. Many of today's parents search for information and support on the Web [21]. In addition, postpartum women who feel isolated or restricted by their baby's schedule experience Web-based resources as useful [22]. In a thematic analysis of motivators and barriers to a Web-based postpartum treatment, it was found that the offered flexibility and anonymity fitted women's postpartum circumstances [23]. This suggests that Web-based treatments may be an appropriate alternative or supplement to conventional face-to-face therapy for postpartum women.
Systematic reviews and one meta-analysis focusing on the perinatal period suggest that Web-based treatments can help improve postpartum depressive symptoms [24][25][26], but so far none are specifically developed for postpartum anxiety [24]. A Web-based survey demonstrated that women with postpartum anxiety are interested in Web-based treatments [27], and a qualitative study of postpartum health care professionals (health visitors) in the United Kingdom reported a need for more treatment options for postpartum anxiety and that Web-based treatments could be useful to address this issue [28].

The What Am I Worried About Treatment
On the basis of the identified interest and need, a self-help treatment for women experiencing moderate or severe symptoms of postpartum generalized anxiety disorder called What Am I Worried About (WaWa) developed in Australia [4] was transformed into a Web-based version called Internet-based WaWa (iWaWa). This study aimed to evaluate the feasibility and acceptability of iWaWa for women with postpartum anxiety problems in England. On the basis of the stage model of behavioral therapy research [29,30], the primary study objectives were to determine study feasibility by examining recruitment and attrition, examine iWaWa's feasibility in terms of engagement and usability, and examine user's acceptability of iWaWa in terms of usefulness, helpfulness, and satisfaction. The secondary objective was to examine potential changes in anxiety over the course of the treatment and compare with a wait-list control group.

Methods
The study received ethical approval from the National Research Ethics Service, London-Dulwich Research Ethics Committee (ref: 15/LO/1827).

Sample Size Calculation
Studies evaluating the feasibility of Web-based treatments for postpartum depression have recruited between 53 to 103 participants in total [31,32]. A power calculation indicated that 27 participants in each group would be required to achieve 95% power at a one-sided 5% significance level. In studies evaluating postpartum depression, Web-based treatments had attrition rates between 11.3% and 62.3%, with an average attrition of 34.2% [31,33,34]. About 18 more participants needed to be recruited to allow for 34.2% attrition. It was therefore aimed for a minimum of 36 participants per group (treatment vs wait-list control) (total=72).

Recruitment
Participants (n=89) were recruited over 8 weeks (March to May 2017) through Facebook, Twitter, and appropriate UK third-party parenthood websites, as well as through posters and flyers in two clinical settings in England (hospital and health visiting clinic). The development of the promotional material was informed by mothers participating in patient and public involvement meetings. Monetary compensation was only offered for taking part in the follow-up interviews.

Eligibility Criteria
Eligible participants had to have given birth in the last 12 months, be aged over 18 years, be living in England, be able to read and write English, have internet access, and have scored ≥5 on the Generalized Anxiety Disorder Scale (GAD-7) [35].
Women were excluded if they were receiving formal psychological treatment at the start of the study, reported self-harm or suicidal ideation, or had a stillbirth or the baby was seriously ill.

Origin and Format
iWaWa is based on the WaWa self-help booklet for postpartum generalized anxiety disorder [4]. A licensing agreement with Monash University allowed researchers at the City, University of London to develop a Web-based version of WaWa for use in England in collaboration with the WaWa development team in Australia.
WaWa is based on cognitive-behavioral and mindfulness principles and consists of 3 sections: (1) Is this for me? (2) Practice, and (3) Understanding. In the first section, concepts such as generalized anxiety disorder, common worries during the perinatal period, and the cognitive-behavioral therapy (CBT) and mindfulness models are explained, and the program is outlined. The section on "Practice" consists of 7 worksheet modules that target life stage-specific anxieties and worries using guided activities. The last section provides background information about the biopsychosocial model of anxiety and a lay language description of CBT and mindfulness theories and practice. For more detailed information about the WaWa program, please refer to [4].
iWaWa Format iWaWa, the Web-based WaWa version, was developed on and hosted by the Qualtrics Platform and a City University of London blog. For the Web-based format, the three main sections were divided into 9 modules (one "Is this for me?" module; seven "Practice" modules; and one "Understanding" module). A link to each module could be found on a password-protected blog page of the iWaWa study website. See Multimedia Appendix 1 for two images of iWaWa. Sessions were made up of multimedia presentations (text, images, and audio) and Web-based interactive material (eg, textboxes, self-assessment with sliders, hotspot graphics).
Participants were advised to start with the first module, but were free to access the remaining modules in any order and as many times as they wished. iWaWa users were also offered optional weekly email and or text-message reminders and weekly 30-min telephone support with each practice module. The iWaWa coach (MA) was a health psychology doctoral student with a master's in clinical psychology. An adapted version of the WaWa Health Professional's Guide was developed, which included checklists to record fidelity of program implementation and participant understanding and progress. No changes were made to iWaWa after the trial started.

Study Design and Procedure
Design Figure 1 illustrates the study design and procedures including data collection time-points and measures. A 2 (groups) by 3 (time-points) randomized controlled trial was carried out. Using a blocked randomization design (generated on the Web), the participants were randomly allocated to an iWaWa treatment group or a wait-list control group. Data were collected at baseline, throughout the treatment, 8 weeks postrandomization, and 12 weeks postrandomization utilizing both quantitative (Web-based questionnaires) and qualitative methods (optional iWaWa module comments and semistructured interviews).

Procedure
The study website contained a link to the Web-based questionnaire consisting of the electronic informed consent procedure, the eligibility questions, and the baseline assessment. Women who were not eligible were provided with links to websites of organizations dealing with postpartum or general mental health problems and advised to contact their general practitioner or health visitor if concerned about their mental health.
Participants were quasi-anonymous. Treatment allocation was revealed to eligible participants via email, and participants created a personal identifier for the iWaWa modules and Web-based assessments. The personal identifier was also used to detect participants signing up multiple times. Treatment group participants were immediately emailed the link and password to the iWaWa program with telephone support, and wait-list control group participants were offered access to iWaWa without telephone support at 8 weeks postrandomization. Treatment group participants received one reminder email to start treatment, and all participants received one reminder email for the 8-week and 12-week follow-up assessments. Participants and the researcher (MA) responsible for the study management and analysis were not blinded.

Study Feasibility
For study feasibility, the following parameters were recorded: (1) recruitment rate and recruitment source, (2) eligibility and consent rates, (3) dropout attrition rates, and (4) completeness of data collection and assessment response rates.

Engagement
Module views (module opened) and completion (all pages of the module were viewed), engagement with interactive components, and the number and duration of iWaWa support calls were recorded. Nonusage attrition rates were calculated.

Usability
Upon completion of each module, participants were asked to rate the module's clarity ("This module was clear and understandable.") on a 7-point Likert scale (1=strongly disagree to 7=strongly agree). At the 8-week postrandomization assessment, the System Usability Scale (SUS) [36] was used to determine treatment usability. The SUS is a 10-item instrument rated on 5-point Likert scale (0=strongly disagree to 4=strongly agree). The SUS has been found to be a highly robust and versatile tool [36] and has previously been used in a study evaluating the feasibility of Web-based treatment for postpartum depression [31]. The SUS was adapted by replacing "the system product" with "iWaWa." Scores were added together and multiplied by 2.5 to convert the original scores to 0-100. A score above a 68 is considered above average and below 68 is below average. Participants were also asked to rate how iWaWa fit into their daily routine and potential future usage on a 7-point Likert scale (1=strongly disagree to 7=strongly agree). Participants were further asked to state any technical issues.

Usefulness
At the end of each module, participants were asked to rate the module's usefulness ("I found this module useful") on a 7-point Likert scale (1=strongly disagree to 7=strongly agree). At the 8-week postrandomization assessment, participants were presented with the statement "I found iWaWa useful" rated on a 5-point Likert scale (1=strongly disagree to 5=strongly agree).

Satisfaction
The Client Satisfaction Questionnaire (CSQ-8) [27,28] was used to assess treatment satisfaction. The CSQ-8 consists of 8 items rated on 5-point Likert scale. The CSQ-8 demonstrated excellent psychometric properties [37]. The CSQ-8 was adapted for this study by substituting "service" with "help" and "program" with "iWaWa." The overall sum ranged from 8 to 32 with higher score indicating higher satisfaction.

Helpfulness
The 8-week postrandomization assessment also included 6 items developed for this study and designed to measure perceived helpfulness with anxieties and worries (eg, "Using iWaWa made it easier to cope with my worries") on 5-point Likert scale (1=strongly disagree to 5=strongly agree).

Mental Health
Anxiety was measured using the GAD-7 [35]. The GAD-7 is a 7-item anxiety measure, and items are rated on 4-point Likert-scale ranging from 0 (not at all) to 3 (nearly every day). It demonstrated validity and reliability in clinical practice and research [35]. It has been suggested that the GAD-7 is a viable postpartum anxiety screening tool [38].
The Depression, Anxiety, and Stress Scale (DASS-21) [39] consists of 21 items rated on a 4-point Likert-scale ranging from 0 to 3. Higher scores indicate more severe symptoms. The DASS-21 has good internal consistency and concurrent validity [40,41].

Participant Characteristics
In line with the Consolidated Standards of Reporting Trials of Electronic and Mobile Health Applications and onLine TeleHealth (CONSORT-EHEALTH) checklist, demographics relevant to the digital divide as well as maternity characteristics were collected as part of the baseline questionnaire: age, ethnicity, education, employment, annual household income, relationship status, availability of computer, laptop, tablet, smartphone, number of previous children, and the number of weeks since giving birth.

Comments
Participants could write an optional comment about their experience at the end of each iWaWa module and in the follow-up assessments.

Follow-Up Interviews and Survey
All treatment group participants (including dropouts) were invited to take part in an optional semistructured phone interview or Web-based survey to collect in-depth information about their treatment experience. Participants gave verbal consent before the start of the interview. Interviews were audio-recorded and conducted by the first author (MA) using a semistructured interview schedule with open-ended questions (see Multimedia Appendix 2). The same questions were used for the Web-based survey for which consent had to be provided electronically. Participants received a £10 Amazon voucher as a compensation for their time.

Quantitative Data
Statistical analyses were performed with SPSS using a P<.05 significance level. Descriptive statistics including means, standard deviations, percentages, and proportions were used to describe the characteristics of the overall sample and the two groups, as well as the iWaWa program feasibility and acceptability and study feasibility. Independent t tests and chi-square tests were used to explore whether participant characteristics differed between the groups or between participants who did and did not complete the follow-up assessments.
For the mental health measures, group differences and differences over time were analyzed using independent and dependent sample t tests. Due to the large amount of missing data for the follow-up assessments, an intention-to-treat analysis was deemed inappropriate [42], and only the data of those completing the assessments were compared. Two-tailed bivariate correlations were conducted to explore whether there is a relationship between anxiety scores and the variables "weeks postpartum" and "number of children."

Qualitative Data
The interview recordings were transcribed verbatim with all identifying information removed. Subsequently, the interview transcripts and the comments on the individual chapters were analyzed using inductive thematic analysis [43]. The software Quirkos was used to ensure systematic coding. The analysis identified general themes emerging form the comments and interviews. Table 1 presents detailed information about participant characteristics of all randomized participants, those lost to follow-up, and those completing the 8-week follow-up assessment.

Recruitment
Of the 89 randomized women, 86 (97%) had heard about the study from Facebook and 3 (3%) from friends.

Dropout Attrition
A total 21 out of 43 wait-list control participants (48.84%) completed the 8-week follow-up assessment. Eight of 46 (17%) treatment group participants responded to the 8-week follow-up assessment (one participant completed only the GAD-7 and DASS-21). There was a significant difference in attrition rates between the groups (P=.002). Four of 46 (9%) women in the treatment group completed the final (12-week follow-up) assessment. One of the four had not completed the 8-week follow-up assessment.

Engagement iWaWa Modules
Of the 46 treatment group participants, 26 participants (56%) viewed at least one module and on average 1.65 modules (SD 2.51; including repeat views). Two participants viewed all modules (4.34%). Figure 3 illustrates the number of module views and completion by the treatment group. Of the 76 modules viewed, 61 (80.26%) were completed. Module 1 was most viewed with a marked reduction thereafter. Engagement with the 14 interactive components within the program ranged from 50% to 100% (mean 69 [SD 0.17]).

Email, Text, and Phone Support
Of the 25 women in the treatment group accessing module 1, 24 (96%) signed up for weekly reminders (email: n=16, text: n=6, email and text: n=2). One woman requested a support call but did not respond when asked about a call date and time.

Usability
The average SUS usability score was 40

Qualitative Treatment Feasibility and Acceptability Outcomes
Qualitative data comprised 31 comments from iWaWa modules and follow-up questionnaires and five interviews (13-18 min). Data saturation was assumed when no new themes emerged from the interviews and comments. Of the interviewees, one completed the first module and the remaining four between 4 to 9 modules.

Themes
Thematic analysis generated 3 key themes (presentation and format, content, and helpfulness) and 10 subthemes. Figure 4 presents a diagram of the themes and associated subthemes. Textbox 1 contains quotes for each theme and subtheme.
Overall, participants described iWaWa as generally useful and straightforward but not user-friendly. Participants reported feeling that it was good to know that something like iWaWa is being developed and that it should be further developed to make it accessible to more women in the same situation.

Accessibility
Participants enjoyed that iWaWa could be accessed from home at a time that suited them, which was reported important with a newborn baby and multiple children.

Anonymity
Women appreciated iWaWa's anonymity. One participant stated that she would have not reached out for help any other way.

Support Option
The weekly email and text messaging reminder option was described as a strength of iWaWa and the support phone calls as a valuable option.

Website Usability
It was reported that iWaWa did not display well on their smartphones and that iWaWa was not very user-friendly and modern. Frustration was caused by having to find the iWaWa link for logging in. All stated they would prefer iWaWa as an easy to use smartphone app.

Support Format
Regarding the support calls, women mentioned the importance of further highlighting the support call option and its purpose and credibility and more frequent reminders. One participant would have preferred a more anonymous option (eg, email or text chat).

Learning About the Principles of Cognitive-Behavioral Therapy and Mindfulness
Women stated to have especially enjoyed the first module and felt the module provided them with "tools" that some were still using, for example, by downloading mindfulness apps.

Relevance and Helpfulness
Women stated that most included topics (anxieties) were generally relevant. Women described it as helpful to learn that other women experience same or similar anxieties.

Relevance
Many participants stated that not all topics were as relevant and that some were too specific, which made them skip modules.
Women with multiple children felt that iWaWa could benefit from making the content more applicable to their situation.

Appropriateness
Several women reported to have experienced the content, especially the unhelpful and helpful actions and examples, as "ridiculous" and "a bit off-putting" and promoting a certain parenting style. It was suggested that the program content should be reflecting a range of parenting styles.

Format Issues
Participants felt that some of the content was repetitive and very "wordy" and could be improved by having more concise and shorter modules. It was mentioned that it was "labor-intensive" to generate their own examples for the exercises and that the exercise examples were described as "hard to relate to." It was suggested to offer the option of using "pre-provided" statements for the exercises.

Theme 3: iWaWa Helpfulness
Of the 5 interviewed women, 2 felt that iWaWa helped with their anxieties, 2 felt that it helped a bit, and 1 said that it probably would have helped if she had done more of the program. All felt that iWaWa could be more helpful with their anxieties if the presentation and content was improved.  Table 2 contains the mental health outcomes for the treatment and wait-list control groups at baseline, the 8-week follow-up, and 12-week follow-up. A total of 28% (25/89) women scored in the mild anxiety range, 42% (37/89) in the moderate anxiety range, and 33% (27/89) in the severe anxiety range on the GAD-7 at the baseline assessment. There were no significant differences between the treatment and wait-list control groups on all mental health measures at baseline. At the 8-week assessment, no significant group differences were found for anxiety (GAD-7 and DASS-21 anxiety). For both groups, anxiety scores significantly reduced from baseline to the 8-week follow-up. There was no significant difference between the 8-week and 12-week follow-up in anxiety scores for the treatment group. Multimedia Appendix 3 illustrates the GAD-7 and DASS-21 anxiety scores for the 3 participants who started the iWaWa program and completed both follow-up assessments. There was no significant correlation between any of the anxiety scores and time since birth and number of children.

Principal Findings
This study aimed to assess the trial's feasibility, iWaWa's treatment feasibility and acceptability, and explore changes in postpartum anxiety in association with iWaWa. Regarding the study's feasibility, the minimum sample size required was exceeded within the relatively short recruitment period (8 weeks). Facebook proved most successful for recruitment. However, there was a high dropout attrition from the study and also a high treatment nonusage attrition. Among women who accessed iWaWa, the treatment was experienced as generally useful and helpful but not user-friendly enough in terms of treatment format and content. Participants felt that iWaWa could be improved by having it as a smartphone app and by making the content more concise and inclusive of different parenting styles. Anxiety levels decreased significantly for both groups from baseline to the 8-week follow-up assessment, but there were no differences between the treatment and wait-list control group. However, due to high drop-out and nonusage attrition, especially in the treatment group, the results for mental health cannot be interpreted reliably and will therefore not be further discussed. The results regarding recruitment and attrition, usability, and acceptability will be discussed in more detail below, including a comparison with previous literature and potential program improvements.

Recruitment and Attrition
Within a relatively short recruitment period, the iWaWa trial successfully recruited more than the minimum calculated sample size through Facebook. The response rate is comparable to similar studies. A study recruiting women with postpartum anxiety for a Web-based online survey through Facebook had a similar response rate (220 respondents over 4 months) [44]. Two studies recruiting women in the United Kingdom with postpartum depression through website advertisement banners for a Web-based treatment had similar (249 respondents over 5 months [33]) and higher response rates (1403 respondents over two waves of 2-week recruitment periods [34]). The successful recruitment might indicate that there is an interest and potential need for a treatment such as iWaWa among postpartum Facebook users. Due to the inability to recruit participants in health care settings, it remains to be investigated whether recommendation or endorsement from health care professionals might have increased iWaWa's recruitment rates.
Dropout attrition in the iWaWa trial was high (49% to 91%). In comparison, in the open pilot study evaluating WaWa, dropout attrition ranged from 39% to 61%. However, it has been pointed out that many trials testing Web-based interventions often suffer from high attrition rates [45]. Due to the lack of other trials of Web-based postpartum anxiety treatments, attrition can only be compared with trials of postpartum depression. Regarding postpartum Web-based treatments, one study evaluating the feasibility for depression with minimal support (Netmums program) also reported a high attrition rate (76%) [34]. The study found that, like this trial, there was an initial high access with a small user subgroup continuing to access and use the program. The authors discussed the role of curiosity, and it has also been suggested that one session may satisfy the user's need [46]. The Netmums program's attrition reduced to approximately 20% at the posttreatment assessment when telephone support was added [33]. Similarly, the Web-based MomMoodBooster program for postpartum depression with telephone guidance also reported comparably very low attrition rates [31,46]. When comparing iWaWa's attrition to postpartum depression trials, it has to be noted that a systematic review found higher Web-based intervention adherence rates for depression than anxiety [47].
There are a variety of factors that could have caused iWaWa's high attrition. Commonly identified reasons for dropout include the burden of the program, program information structure, content relevance, level of support, technical access issues, time constraints, lack of motivation, and improvement of the group [34,47,48]. The potential role of these factors regarding iWaWa's high attrition will be briefly discussed.
This study suggests that some women indeed experienced the access, length, and exercises of iWaWa as a burden. With the infant's demanding schedule, it is possible that iWaWa participants felt a lack of motivation or experienced time constraints. For Web-based postpartum depression treatments, adherence was high when scheduled support was offered [31,33,46]. Scheduled support was part of the original WaWa treatment and valued as strength of the treatment [4]. On the basis of a survey which found that telephone support was not the preferred mean of support among women with postpartum anxiety [44], it was decided for iWaWa's telephone support to be optional. Scheduled support might improve adherence of women wanting this type of support, but it might also put off women who do not feel the need or find it unsuitable. Offering to opt in for scheduled support at the treatment start might be an alternative for future iWaWa versions. Regarding content relevance, a qualitative study suggested that being able to identify with a an online intervention program helps with adherence in Web-based psychological interventions [48]. As some of iWaWa's topics were not experienced as relevant, it could therefore be that some participants logged into iWaWa but dropped out because they experienced the topics as irrelevant. Concerning symptom improvement, a recent systematic review and meta-analysis found that the prevalence of postpartum anxiety decreases from 1-4 weeks to 5-12 weeks [1], and it could therefore be that the participant's symptoms improved and they no longer felt the need for iWaWa. In addition, almost half of the participants scored in the severe to extremely severe range of stress. It might be that participants were in need for stress management techniques, which could be incorporated in future iWaWa versions. The iWaWa program used an organic information structure design that allowed users to freely explore the modules. The use of a tunnel design, in which users navigate through content in a sequential order, has been identified as less likely to overwhelm users with options [49] and may increase use [50].

iWaWa's Usability and Acceptability
Participants enjoyed iWaWa's accessibility, anonymity, and weekly reminders, as well as the introduction to the principles of CBT and mindfulness. This is in line with previous qualitative research regarding Web-based treatments for postpartum depression [23,32,51], as well as postpartum UK health care professionals (health visitors) [52].
iWaWa was rated and experienced as generally useful and helpful but not user-friendly enough. The iWaWa content was experienced as too long. A preference for brief modules was also identified by Web-basedsurveys among a sample of adults [53] and among women with postpartum anxiety [44]. Participants also felt that iWaWa's content was not inclusive of different parenting styles. WaWa's content was found to be acceptable in a small sample (n=7, in the posttreatment evaluation interview) pilot study in Australia [4]. It might therefore be important to investigate in more depth the needs of a larger and more diverse sample of women with postpartum anxiety so that iWaWa's content and format can be adapted to better meet their needs.
Women in this study also felt that not all topics were relevant. The need for Web-based treatments to be relevant to their own needs and circumstances was also discovered among women with postpartum depression [23,32]. Future iWaWa versions might benefit from presenting users with content most relevant to them (eg, anxiety topic needs and relevance assessment before the treatment starts).
Interactive components with space for responses were previously found to be valued among women with postpartum depression [23]. Even though most iWaWa users engaged with the exercises, many experienced them as difficult. The ease of usage of the interactive components seems important among iWaWa users, and therefore exercises of future iWaWa versions should be tested by potential users before implementation (eg, think-out aloud technique).
Regarding the format, iWaWa participants experienced the log-in process as difficult. The log-in process was also identified as difficult by women testing a Web-based postpartum depression treatment [32]. Participants also expressed that iWaWa was not smartphone-friendly, which was also reported by women testing a Web-based treatment for postpartum depression [32]. The preference for a smartphone-compatible treatment was also found in a survey among women with postpartum anxiety [44]. iWaWa was smartphone compatible, but iWaWa as a smartphone app might improve the ease of access and presentation on smartphones.

Limitations
The generalizability of the results of this study is compromised due the use of convenience sampling and a homogenous sample. Findings may therefore not be representative of women from different cultural or ethnic backgrounds, lower socioeconomic status, and more severe anxiety. In addition, most women were recruited through Facebook, so findings are limited to this self-selected pool of women. However, the homogeneous nature of this sample can also be a strength, as results can be generalized for this specific group. Furthermore, no incentives were offered during the enrollment, allowing for a sample with a genuine and intrinsic need. The generalizability may also be affected by the fact that the anxiety status was established by a screening instrument and not by a diagnostic tool. However, the GAD-7 is a frequently used anxiety screening tool and has been suggested as suitable for postpartum anxiety [38]. In addition, diagnostic interviews are less anonymous and iWaWa's anonymity was highlighted as an important strength by the participants.
High dropout and nonusage attrition may have also biased the results. Therefore, findings regarding iWaWa's usability, acceptability, and mental health changes are limited to the experiences and views of a small sample. None of the women who did not start iWaWa took part in the follow-up interviews; so, no knowledge could be gained regarding what caused the early dropout.
The interviewer of this study was MA, who is a doctoral student investigating Web-based treatments for postpartum anxiety with personal experience related to this subject. These experiences may affect the collection, analysis, and interpretation of the data. Therefore, several actions were taken to minimize the likelihood of this risk. Participants were aware that the interviewer was the main study lead, but reassured of the importance of any feedback (positive and negative) for improving iWaWa. The qualitative analysis also included comments from the iWaWa modules and the follow-up assessment in which women might have felt more comfortable providing negative feedback. MA kept a reflective journal to consider how the treatment and interviewee responses affected her own views on iWaWa throughout data collection, analysis, and reporting. An effort was made to consider this when analyzing the data. Interviewees were offered monetary compensation for their time, which might have confounded their responses.

Conclusions
This study demonstrated that there is an interest in a postpartum anxiety Web-based treatment like iWaWa. However, the iWaWa study and program in the current format is not yet feasible and acceptable, and due to high dropout rates, the results on the impact of iWaWa on anxiety cannot be interpreted reliably. Nonetheless, the study revealed strengths and weaknesses of the iWaWa content and format, as well as highlighted potential areas of improvements. As a first study investigating the usability and acceptability of Web-based treatment specifically targeted at postpartum anxiety, these results provide useful information about Web-based treatment preferences that can help improve iWaWa and inform research and development to optimize usability, acceptability, and Web-based treatment adherence in this population. This study also contributes to filling the gap in evidence-based self-help for mild-to-moderate postpartum anxiety symptoms.