Sexual Health

All patients involved in this study fulfilled the ACR/EULAR classification criteria for SSc^{43 (link)}. Plasma samples from all patients and healthy individuals were prepared from the whole blood collected into commercially available EDTA-treated tubes. For the cross-sectional analysis, plasma samples were obtained from 92 Caucasian patients with systemic sclerosis (SSc) and 92 age- and sex-matched Caucasian healthy controls. For the longitudinal analysis, plasma samples were obtained prospectively at baseline, and 1, 6, and 12 months thereafter from 30 Caucasian patients with SSc-ILD with active alveolitis without pulmonary arterial hypertension who underwent a routine 6-month (n = 16) or 12-month (n = 14) treatment with i.v. cyclophosphamide (CPA, 500 mg/m² monthly). Active alveolitis was defined as the presence of areas of ground-glass attenuation on high-resolution computed tomography (HRCT) and reduced levels of diffusing lung capacity for carbon monoxide (DLCO) and/or forced vital capacity (FVC), as described elsewhere^{44 (link)}. Other SSc-related clinical features were assessed according to generally accepted definitions and recorded, such as the presence of pulmonary arterial hypertension, renal, cardiac and gastrointestinal involvement, Raynaud's phenomenon, and digital ulcers^{45 (link)}. Skin involvement was evaluated using the modified Rodnan skin score (mRSS)^{46 (link)}. Disease activity was determined by the European Scleroderma Study Group (ESSG) SSc activity score^{47 (link)}. Pulmonary function tests (PFT) were routinely performed using standard methods, in accordance with the ATS recommendations^{48 (link)}. The DLCO was measured by a single-breath method using a gas mixture of 0.2% CO and 8% helium, with correction for hemoglobin. Peripheral oxygen saturation (SpO₂) was measured by a handheld pulse oximeter (CR-100, Noramedica, Czech Republic). In the longitudinal analysis PFTs were performed at baseline, and 6 and 12 months thereafter, and the results are expressed as a percentage of the normal predicted values based on the patient’s sex, age, and height. The research was confirmed by the local ethics committee at the Institute of Rheumatology in Prague, and each patient signed an informed consent form. All methods were performed in accordance with the relevant guidelines and regulations.

Full details of the methods used in Natsal-3 have been reported elsewhere.20 (link), 21 Briefly, we used a multistage, clustered, and stratified probability sample design. 1727 postcode sectors (geographical units used for sorting mail) throughout Britain were used as the primary sampling units and were randomly allocated to one of eight periods of fieldwork that took place between Sept 6, 2010, and Aug 31, 2012, with each period lasting about 3 months.
Within each primary sampling unit, 30 or 36 addresses were randomly selected and then assigned to interviewers from NatCen Social Research. To allow detailed exploration of behaviours in the age group at highest risk of some sexual health outcomes (eg, unplanned pregnancy and sexually transmitted infections), we oversampled individuals aged 16–34 years. We randomly allocated addresses to either the core sample (in which all individuals aged 16–74 years were eligible) or the boost sample (in which only individuals aged 16–34 years were eligible). Letters and leaflets giving background information about Natsal-3 were sent to sampled addresses before visits began.
Interviewers visited all sampled addresses, identified residents in the eligible age range, and randomly selected one individual to be invited to participate in the survey using a Kish grid technique. Participants then completed the survey in their own homes through a combination of face-to-face interviews with computer-assisted personal interview and a self-completion format with computer-assisted self-interview. Interviewers were present in the room while participants completed the computer-assisted self-interview and could provide assistance as necessary, but did not view responses. On completion of computer-assisted self-interviews, answers could not be accessed by interviewers. No names or other potentially identifying information was attached to the interviews. Interviews lasted about 1 h on average. Participants received a £15 gift voucher as a token of appreciation. An anonymised dataset will be deposited with the UK Data Archive, and the complete questionnaire and technical report will be available on the Natsal website on the day of publication.
These methods are broadly the same as those used in Natsal-1 and Natsal-2. However, in Natsal-1, paper was used (rather than computers) during face-to-face interviews and self-interview. Descriptions of the development stages of previous surveys are available elsewhere.9 , 10 , 11 (link), 22 (link), 23 , 24 (link) Most questions in Natsal-3 were identical to those in Natsal-1 and Natsal-2, including questions about age and circumstances of first sexual intercourse, sexual practices, experiences with sexual partners, details of most recent partners, and attitudes. Questions added in Natsal-3 included those about health problems that could affect sexual lifestyles, sexual function and satisfaction, a screen for depressive symptoms, non-volitional sex, and unplanned pregnancy.20 (link), 21 The questionnaire underwent thorough cognitive testing and piloting, as previously reported.²⁵
As in Natsal-1 and Natsal-2, we weighted Natsal-3 data to adjust for the unequal probabilities of selection in terms of age and the number of adults in the eligible age range at an address. After application of these selection weights, the Natsal-3 sample was broadly representative of the British population compared with 2011 Census figures,26 , 27 although men and London residents were slightly under-represented. Therefore, as in previous surveys, we also applied a non-response post-stratification weight to correct for differences in sex, age, and Government Office Region between the achieved sample and the 2011 Census (appendix).26 , 27
We compared data for participants aged 16–44 years in each survey. This age group was common to all three surveys. Information about variables that were compared was derived from identically worded questions. All three surveys had been weighted for differential selection probabilities. Natsal-1 was post-stratified to 1991 Census figures and Natsal-2 to 2001 Census figures, with procedures described for Natsal-3,20 (link), 21 which allowed us to make comparisons between the three surveys. However, there are minor differences from the weighting schemes used in previous reports.9 , 10 , 11 (link), 12 (link), 13 (link), 23
The Natsal-3 study was approved by the Oxfordshire Research Ethics Committee A (reference: 09/H0604/27). Participants provided oral informed consent for interviews.

This study used an explanatory, sequential mixed methods design, in which quantitative and qualitative data were obtained to provide a comprehensive understanding of the factors driving Black women’s willingness to use mobile apps for sexual health and HIV prevention. To understand the intersection of age, race, and gender regarding HIV prevention interventions, particularly among Black women, a voluntary, anonymous survey was conducted among Black women enrolled in college in the Atlanta Metropolitan Area. These data helped us understand their perceptions regarding sexual health and their willingness to use reproductive mHealth apps. In total, 65 responses were gathered and analyzed using descriptive statistics. To complement quantitative data collection, a focus group was conducted with college-aged Black women. Written informed consent was obtained from all participants during both the phases of the study. All data were deidentified, and participants were assigned unique identification numbers. The participants were not compensated for the quantitative phase of the study. Those who participated in the qualitative phase received a US $30 gift card for their participation.