Phone Number Research Articles

Phone numbers, emojis and GIF files as electronic signatures

Due to constant technological progress, the conclusion of electronic contracts has become common. Thus, electronic signatures are used to identify the parties and to express their agreement regarding the content of the contract. The use of these electronic signatures led to emojis being used in electronic contracts. The judicial cases in which these types of electronic signatures are apparently used, must be analyzed, as it is necessary to determine the probative power of the electronic document that contains this specific signature. We would also like to mention that a theoretical analysis of GIF files and phone numbers as electronic signatures is necessary in order to prevent certain legal interpretation problems that might arise in future litigation.

Blockchain and Machine Learning Integration for Data Privacy and Security

Purpose: In today's world, data is gathered without any particular objective in mind; every action taken by a computer, or a human being is documented, and the data is studied in the future, if it is considered important to do so. The data will be subjected to several steps for analysis by a variety of parties, which raises the issue of trust in this context. There is a risk that the organizations involved in the analytical stages may abuse the data, which might contain private or sensitive information. Consequently, data privacy considerations should be carefully considered at this time. Methodology/Findings: A definition of "data privacy" is the practice of limiting access to information according to how important it is. People are usually very comfortable giving out their names to strangers, but they'll wait to give out their mobile phone numbers until they're more familiar with the individual. In this era of digital technology, important personal information is often the target of individuals' efforts to protect their data. From a business's point of view, data privacy encompasses more than just employees' and consumers' private information. Data privacy issues are often believed to be a barrier to the widespread adoption of AI and ML-driven technology. The reason for this is that ML can only be trained and tested on very large data sets. Implications to Theory, Practice and Policy: Imagine a world where trust is impossible to establish; here is where Blockchain technology might be useful. Blockchain uses the data anonymously. In this study, we provide a solution that ensures data security by integrating Blockchain technology with machine learning (Alfandi et al., 2020).

A Novel Approach of Cloud Computing Network for Authentication and Security Enhancement of IoT Enabled Cancer Forecasting System

Recently, a variety of approaches have been employed to address a broad spectrum of real-world issues; these methodology cover a variety of areas, including healthcare systems. Previous researchers concentrated on health-care monitoring software. It had several shortcomings, such as poor health-care data storage, time, expense, and processing complexity. This paper proposes a unique IoT-enabled and secured clinical monitoring paradigm to address these issues. Initially, implant several sensors to gather information on vital indicators like body temperature fluctuation. Phone numbers, marital status, heart rate deviation, residence, name, age, and blood pressure are among the patient's health information. The IoT medical sensor dataset is used in this investigation. During pre-processing, extra unnecessary attributes are removed, resulting in data size reduction and normalization. A convolutional neural network supporting the classification of cancer sickness that is based on the improved teaching-learning optimization (CNN-ITLO) method. The CNN-ITLO model ascertains whether or not the patient is cancer-prone based on the sensor input. The management of the hospital receives the gathered data after which it is analyzed. Lastly, the homomorphic encryption approach is used to encrypt and store the patient's data on the cloud. The Java platform will be used to carry out the recommended work. According to the experiment results, the suggested method performed better than current cutting-edge practices.

A hybrid artificial intelligence framework for enhancing digital forensic investigations of infotainment systems

Infotainment systems in vehicles have become important sources of digital evidence in forensic investigations. Analyzing data from these systems can provide valuable insights into a suspect's activities and interactions. In this paper, we propose a hybrid artificial intelligence (AI) framework that combines unsupervised learning using K-means clustering and language model analysis to enhance the forensic analysis process. The proposed methodology was applied to two distinct datasets from Hyundai and Mitsubishi infotainment systems. In the Hyundai dataset, the recall for contact names and phone numbers improved by 18% and 3% respectively when compared to clustering alone. Similarly, in the Mitsubishi dataset, the recall of song names improved by 2%. In addition, this hybrid approach enabled the discovery of more forms of forensically-relevant data stored in the infotainment systems, such as geographical locations and connected devices, that would have been infeasible to find with either manual analysis or clustering alone. Despite the presence of some hallucinations, the combination of these techniques resulted in improved ease of analysis and increased recall, demonstrating the potential of this hybrid approach in forensic investigations.

7-Tesla evidence for columnar and rostral-caudal organization of the human periaqueductal gray response in the absence of threat: a working memory study.

The periaqueductal gray (PAG) is a small midbrain structure that surrounds the cerebral aqueduct, regulates brain-body communication, and is often studied for its role in "fight-or-flight" and "freezing" responses to threat. We used ultra-high field 7-Tesla fMRI to resolve the PAG in humans and distinguish it from the cerebral aqueduct, examining its in vivo function in humans during a working memory task (N = 87). Both mild and moderate cognitive demand elicited spatially similar patterns of whole brain BOLD response, and moderate cognitive demand elicited widespread BOLD increases above baseline in the brainstem. Notably, these brainstem increases were not significantly greater than those in the mild demand condition, suggesting that a subthreshold brainstem BOLD increase occurred for mild cognitive demand as well. PAG response was group-aligned and examined with subject-specific masks. In PAG, both mild and moderate demand elicited a well-defined response in ventrolateral PAG (vlPAG), a region thought to be functionally related to anticipated painful threat in humans and non-human animals-yet, the present task posed only the most minimal (if any) "threat", with the cognitive tasks used being approximately equivalent to remembering a phone number. These findings suggest that the PAG may play a more general role in visceromotor regulation, even in the absence of threat.Significance statement The periaqueductal gray (PAG) is thought to control survival-related behavior, and is typically studied using experiments that manipulate threat. Others have proposed that the PAG plays a more general role in bodily regulation, but studies examining PAG function outside of threat-based experimental contexts are rare. We used high-resolution fMRI to examine PAG response in humans during a working memory task, which involves minimal threat. Moderate cognitive demands elicited a well-defined response in ventrolateral PAG, a functional subregion thought to coordinate a "freezing" response to threat. A task where threat is minimal elicited a clear fMRI response in one of the most well-known survival circuits in the brain, which suggests the PAG supports a more general function in brain--body coordination.

SMS and GPS based Fisherman Tracking System using IOT

Fishermen facing more challenges because the sea border and location cannot be easily identifiable. To ensure the safety of the fishermen, the location should be tracked. In this system, the location can be displayed by latitude and longitude coordinates and also sends data through SMS to the coastal guard and fishermen mobile phone numbers.

Peculiarities of conducting investigative (search) actions during the investigation of the enforced disappearance of a person

The article outlines the tactical principles of conducting such investigative (search) actions: inspection (last known whereabouts of the victim, her place of residence, probable place of the incident, vehicle owned or used by the person, things and documents); interrogation (of witnesses); search.
 On the basis of studied criminal proceedings, taking into account the specifics of committing illegal acts related to the enforced disappearance of a person, such investigative (search) actions are divided according to the territorial principle, in particular, when: a person disappeared on the territory controlled by Ukraine; the person disappeared in the territory not controlled by Ukraine. The peculiarities of the tactics of conducting investigative (search) actions - examination, questioning of the applicant and other eyewitnesses about the sources of the reported information and the known circumstances of the person’s disappearance are highlighted.
 It has been established that the purpose of conducting an inspection of the scene of the incident during the investigation of the enforced disappearance of a person is to: identify and record material evidence, traces, objects that are important for criminal proceedings; verification of testimony of witnesses about the circumstances of a criminal offense; clarification of the situation and circumstances of the criminal offense under investigation. Also, an important investigative (search) action during the investigation of crimes based on the fact of the enforced disappearance of a person is the questioning of a witness. First of all, we are talking about the questioning as a witness of the applicant who reported the disappearance of the person. During the interrogation of the witnesses, it is necessary to find out all the circumstances of the event known to them: time, place of the crime; circumstances preceding the commission of the crime; identity of the victim and possible kidnappers; if these persons are unknown to them - signs of their appearance, etc. The exact time the person left the last place of stay, the possible direction and route of movement, mobile phone number and IMEI of the subscriber, data on registration in social networks and e-mail inbox are subject to establishment. The specifics of the relationship between the applicant and the victim are clarified.

Insider Threats to the Military Health System: A Systematic Background Check of TRICARE West Providers.

To address the pandemic, the Defense Health Agency (DHA) expanded its TRICARE civilian provider network by 30.1%. In 2022, the DHA Annual Report stated that TRICARE's provider directories were only 80% accurate. Unlike Medicare, the DHA does not publicly reveal National Provider Identification (NPI) numbers. As a result, TRICARE's 9.6 million beneficiaries lack the means to verify their doctor's credentials. Since 2013, the Department of Health and Human Services' (HHS) Office of Inspector General (OIG) has excluded 17,706 physicians and other providers from federal health programs due to billing fraud, neglect, drug-related convictions, and other offenses. These providers and their NPIs are included on the OIG's List of Excluded Individuals and Entities (LEIE). Patients who receive care from excluded providers face higher risks of hospitalization and mortality. We sought to assess the extent to which TRICARE screens health care provider names on their referral website against criminal databases. Between January 1-31, 2023, we used TRICARE West's provider directory to search for all providers within a 5-mile radius of 798 zip codes (38 per state, ≥10,000 residents each, randomly entered). We then copied and pasted all directory results' first and last names, business names, addresses, phone numbers, fax numbers, degree types, practice specialties, and active or closed statuses into a CSV file. We cross-referenced the search results against US and state databases for medical and criminal misconduct, including the OIG-LEIE and General Services Administration's (GSA) SAM.gov exclusion lists, the HHS Office of Civil Rights Health Insurance Portability and Accountability Act (HIPAA) breach reports, 15 available state Medicaid exclusion lists (state), the International Trade Administration's Consolidated Screening List (CSL), 3 Food and Drug Administration (FDA) debarment lists, the Federal Bureau of Investigation's (FBI) list of January 6 federal defendants, and the OIG-HHS list of fugitives (FUG). Our provider search yielded 111,619 raw results; 54 zip codes contained no data. After removing 72,156 (64.65%) duplicate entries, closed offices, and non-TRICARE West locations, we identified 39,463 active provider names. Within this baseline sample group, there were 2398 (6.08%) total matches against all exclusion and sanction databases, including 2197 on the OIG-LEIE, 2311 on the GSA-SAM.gov list, 2 on the HIPAA list, 54 on the state Medicaid exclusion lists, 69 on the CSL, 3 on the FDA lists, 53 on the FBI list, and 10 on the FUG. TRICARE's civilian provider roster merits further scrutiny by law enforcement. Following the National Institute of Standards and Technology 800, the DHA can mitigate privacy, safety, and security clearance threats by implementing an insider threat management model, robust enforcement of the False Claims Act, and mandatory security risk assessments. These are the views of the author, not the Department of Defense or the US government.

Are We Providing Enough Information to the Pathologists? An Audit of Filling of Histopathology Request Forms for Surgically Resected Tumours.

To analyse quantitatively the adequacy of demographics of clinical information and highlight specific areas of neglect, by assessing the adequacy of filling out histopathology request forms. Clinical Audit. Place and Duration of the Study: Department of Pathology, Dow University of Health Sciences (DUHS), Karachi, Pakistan, from January to September 2021. A retrospective audit was carried out on the request forms of surgically resected tumours and biopsies. The recorded details of the patients' demographics and biopsy, clinical history and examination, and intraoperative findings were analysed. Out of 175 forms, patients' names were written in 174 (99.4%) while medical record numbers were written in 113 (64.6%). The doctors' names were given in 172 (98.3%) forms and phone numbers in 34 (19.4%). A clinical diagnosis was provided in 164 (93.7%) forms, while 152 (86.9%) forms correctly entered the biopsy site. Sixty-seven (38.3%) forms included the correct nature of the biopsy. Relevant operative details were provided in half of the forms. Symptoms and their duration were mentioned in 144 (82.3%) and 100 (57.1%), respectively. The form-filling rate was the same for both benign and malignant tumours. This study shows that in a significant proportion of cases, complete relevant information is not provided to the histopathologists on request forms for logistics. Histopathology, Request forms, Tumours, Audit.

Predict and Optimize Financial Services Risk Using AI-driven Technology

With the rapid development of internet technology, many industries have embarked on a digital transformation. However, while the Internet has brought convenience to users, it has also become a breeding ground for criminals to commit fraud. On the one hand, a large number of users on the Internet more or less left data, criminals can use this information to practice accurate fraud users, improve the success rate of fraud; On the other hand, online financial transactions such as banking and e-commerce also provide more opportunities for criminals to commit fraud. Therefore, all kinds of fraud methods emerge in an endless flow, through the telephone, information, fishing and other means of fraud, not only to bring hundreds of millions of losses to society every year, but also to the security of people's lives have a huge threat. Monitoring and preventing online fraud is an important part of the cybersecurity industry. For known network fraud, based on the domain name of the phishing site, the account number and mobile phone number that send fraudulent information, simple and effective monitoring and defence can be carried out through the blacklist. However, it is difficult for traditional means to effectively defend against undocumented fraud. With the development of machine learning technology, it is the main research direction of fraud detection methods to discover the information sources and characteristics of information content through machine learning technology, and make real-time and continuous accurate judgments. This paper realises credit fraud detection by generating adversarial network technology, so as to prevent network security risks.

Demonstrating Spoofability of an Originating Number when Sending an SMS using SMPP

The short message service (SMS), a service for exchanging texts via mobile networks, has become a universal means of communication. SMS is a mechanism for sending a text message to a specific mobile phone number. Its protocol enables the sender to specify the destination phone number but not the originating number. However, the short message peer-to-peer (SMPP) protocol, which forwards SMS messages, enables the sender to specify the originating number. If the SMPP protocol allows the sender to specify another person’s phone number as the originator, an attacker can use it to send a short message impersonating another person. In this study, short messages were sent from an SMPP gateway service with any phone number specified as the originator, and their delivery to the Japanese mobile network was verified. All the verified mobile network operators (MNOs) were able to spoof the origin to any international phone number, and one MNO was able to spoof it to any national phone number. The results of this study reveal that SMPP can potentially be exploited to spoof the originating number of an SMS. Furthermore, a threat scenario was devised using spoofing and mitigation measures.

Constructional sources of durational shortening in discourse markers

Abstract Using naturally occurring data from Spanish from Madrid, this study is the first to analyze durations of the Spanish word decir ‘to say, to tell’ both as a verb with prepositional meaning and as part of the reformulating construction [es decir] ‘that is to say’ (N = 388). We show that, although it is neither highly grammaticalized nor frequent, [es decir] undergoes phonological reduction to a significantly greater degree than the more frequent lexical source decir ‘to say’. Results of linear mixed-effects models predicting target duration suggest these durational differences cannot be explained due to conditioning factors of the target context controlled in this analysis (speech rate of the target word context, predictability of following words, number of phones, distance from pause). They do not appear to stem from an accumulation in memory of patterns of likelihood of use in those conditioning environments. We propose that [es decir] is stored as a lexical unit that contains as part of the lexical representation shorter word durations relative to the lexical form decir and that this durational shortening is part of the [reformulator] construction.

Access to struct members and undefined behavior of C code

During software development, novice developers usually receive a lot of error messages and just warnings of various kinds. And if the code simply won't run when there are errors, then the program usually starts when there are various warnings. And here it is important to understand what consequences the presence of warnings of various kinds can lead to. This work aims to study the code's undefined behavior when working with struc-tures in the C programming language when issuing a corresponding compiler warn-ing about returning the address of a local or temporary variable. In the procedural programming language C, there is an ancestor of the OOP class — the structure struct, which encapsulates only the state of the entity. And the question arises — is it possible to work with separate components-fields of such a structure analogously to OOP languages? For research, a simple structure was taken, which contains information about the person's name, surname, and phone number. To access parts of the structure, pseudogetters were used — functions that returned a pointer to the corresponding part of the structure. The research was conducted in the Visual Studio 2019 environment under the control of the Windows 10 operating system when the default C language standard - MSVC and the more modern ISO standard C17 (2018) was selected in the project settings. As a result, a truly undefined behavior of the code was obtained, when the re-sult of the work of the code fragment (function call) depends on many factors: the length of the array, the standard of the C language, the position of a certain part in the structure. An attempt to conduct similar research under the control of the Linux Mint oper-ating system using the gcc compiler version 5.4 was unsuccessful. When compiling the code, a similar warning about returning the address of a local variable was also issued, as in the case of Visual Studio. But when the program was launched, it sim-ply crashed with a message about a segmentation error. Thus, both the Visual Studio 2019 compiler and the gcc compiler warned us about undefined code behavior. But this uncertain behavior was radically different for operating systems and compilers. If after gcc under the Linux OS, the code simply does not work at all and the program stops its work with a segmentation error mes-sage, then after Visual Studio under Windows, inexperienced developers with im-proper testing and verification of the code can miss the code that "does not always work", which can lead to unexpected results, not always pleasant, to say the least. And that's why software developers, especially beginners, should pay attention not only to compilation errors but also to warnings, even if the code works.

Fake Reviews Identifying Machine Learning Technology on Online Food Porters By IJISRT

Wherever we go we will definitely look for food without any time limit. The food is an all-time emotion for everyone. Mainly if anyone visits the new place, he/she is excited to look for good food within less budget, with good management, maintenance and neatness. Zomato is a digital platform that serves as a one-stop destination is ordering food from various restaurants. It users with an extensive data set of restaurants, menus, user reviews, and ratings, allowing them to browse. Zomato is such an interesting app which provides users with more comforts like how many users are approaching to the Zomato, ratings, reviews, restaurants data sets, fast hand delivery, to easily track the order by push up notifications or delivery boy phone number. Mainly Zomato has many facilities whatever food we need we can easily order within seconds. The Zomato has many different food items in different locations within the city/town but some times the restaurants are closed early. Mostly everyone looks for the best biriyanis within their area because the biriyani is not a food but its an heartful emotion who really look for it. Can use supervised machine learning algorithms as logistic regression, naive Bayes or support vector machines, classify the reviews as fake or genuine based on this feature. Every order served by the delivery boy has the charge for delivery. In the present modernized world, fame of food applications is expanding because of usefulness, view, book or request effectively by not very many snaps on telephone. Online reviews have become very easy to take users insight to get the good food in this app. has made it is solid and is currently present in 22countries with more than 1,000,000 eateries around the world and gets 1.25 million orders day to day.

A Systematic Review of NT-proBNP as Prognostic Biomarker for Preeclampsia Complications

Background: Preeclampsia can lead to maternal and fetal complications due to its ability to cause multiple organ disorders. Interestingly, N-terminal pro-brain-type natriuretic peptide (NT-proBNP) levels were higher in preeclampsia than in non-preeclampsia, representing cardiovascular mal¬function as the potential cause. Moreover, NT-proBNP also has a potential role in predicting complications that will arise in preeclampsia. This systematic review was performed to determine the role of NT-proBNP plasma levels in predicting maternal and fetal complications in preeclampsia.Subjects and Method: This systematic review was conducted based on PRISMA-P by previous observational study from scientific databases, namely Hinari, Cochrane Library, ScienceDirect, Scopus, and grey literature in OCLC’s OAISTER between 2006 and 2021. The search keyword used were ((NTproBNP) OR (NT-proBNP) OR (N-terminal pro-BNP) OR (N-terminal pro-Brain Natriuretic Peptide)) AND ((preeclampsia) OR (pre-eclampsia)) AND (pregnancy complications). Newcastle - Ottawa Quality Assessment Scale (NOS) was used to assess quality of included studies.Results: After study selection, five studies from 156 studies were considered eligible and selected in this systematic review. The results showed that pre-eclampsia complications occurred with NT-proBNP levels above 500 mg/dL, which cardiovascular complications may occurred above 700 mg/dL. NT-proBNP levels were higher in women with maternal complications such as placental abruption, HELLP (Hemolysis, elevated liver enzyme levels, and low platelet levels) syndrome, eclampsia, pulmonary oedema, congestive heart failure, cerebrovascular accident, renal dysfunction, and hypertensive retinopathy. Furthermore, increased NT-proBNP levels were associated with fetal growth restriction, resulting in low birth weight. NT-proBNP was significantly higher in pregnant women due to a combination of pre-existing volume overload and NT-proBNP clearance dysfunction in kidney. Conclusion: NT-proBNP levels were associated with adverse outcomes in preeclampsia. NT-proBNP serum levels could be used to predict maternal-fetal complications in preeclampsia. Keywords: preeclampsia, fetal, maternal, complications, NT-proBNP Correspondence: Aiman Hilmi Asaduddin. Faculty of Medicine, Universitas Sebelas Maret. Jl. Ir. Sutami 36A, Surakarta 57126, Central Java. E-mail: aimanhilmi02@student.uns.ac.id. Phone number: +62 85726562060.

Insufficient Answer During the Public Health Emergency: A Lesson from the Persistence of Food Insecurity in Low-Income Communities

ABSTRACT Cohort study in deprived communities to investigate the persistence of food insecurity (FI) during the COVID-19 was conducted. Sample were derived from a list of mobile phone numbers provided by community leaders and local nonprofit organizations. Temporal trends and prevalence ratios of FI persistence, categorized as “never,” “occasional FI,” “consistent FI,” were calculated. A total of 302 households completed three assessments, the majority nonwhite women. During the follow-up, families covered by social assistance increased; however, their income decreased (p < 0.05). 33% were “consistent,” and 46% “occasional” FI. Permanent difficulties accessing gas canisters, hygiene products, and hand sanitizers were observed.

The Effects of a Novel Treatment for Hemianopic Dyslexia on Reading, Symptom Load, and Return to Work.

Reading disorders are frequent in homonymous hemianopia and are termed hemianopic dyslexia (HD). The existing treatment methods have shown improvements in reading speed, accuracy, and eye movements during reading. Yet, little is known about the transfer effects of such treatments on functional, reading-related tasks of daily life, e.g., reading phone numbers, finding typing errors or text memory. In addition, little is known about the effects on symptom load and return to work. Here, we examined a new reading therapy entailing three different methods-floating text, rapid serial visual presentation (RSVP) of single words, and the moving window technique-and evaluated their efficacy. Twenty-seven chronic HD patients were treated in a baseline design with treatment-free intervals before and after a treatment period of several months. HD was assessed with a battery of reading tests and a questionnaire about subjective symptom load at four time-points. Patients received all three reading therapies over several weeks. The results show significant and stable improvements during treatment within all measures. Approximately 63% of treated patients returned to work after the therapy. We concluded that our novel HD treatment led to widespread and lasting improvements in reading performance, generalized to functional reading tasks and reduced symptom load, and the majority of patients were able to return to work.

Improving the Efficiency of Outbound CATI As a Nonresponse Follow-Up Mode in Address-Based Samples: A Quasi-Experimental Evaluation of a Dynamic Adaptive Design

Abstract This article evaluates the use of dynamic adaptive design methods to target outbound computer-assisted telephone interviewing (CATI) in the California Health Interview Survey (CHIS). CHIS is a large-scale, annual study that uses an address-based sample (ABS) with push-to-Web mailings, followed by outbound CATI follow-up for addresses with appended phone numbers. CHIS 2022 implemented a dynamic adaptive design in which predictive models were used to end dialing early for some cases. For addresses that received outbound CATI follow-up, dialing was paused after three calls. A response propensity (RP) model was applied to predict the probability that the address would respond to continued dialing, based on the outcomes of the first three calls. Low-RP addresses were permanently retired with no additional dialing, while the rest continued through six or more attempts. We use a difference-in-difference design to evaluate the effect of the adaptive design on calling effort, completion rates, and the demographic composition of respondents. We find that the adaptive design reduced the mean number of calls per sampled unit by about 14 percent (relative to a modeled no-adaptive-design counterfactual) with a minimal reduction in the completion rate and no strong evidence of changes in the prevalence of target demographics. This suggests that RP modeling can meaningfully distinguish between ABS sample units for which additional dialing is and is not productive, helping to control outbound dialing costs without compromising sample representativeness.

Pengembangan Kompetensi Pemasaran Digital bagi Wirausaha Kelompok Buruh Migran dan Keluarganya

The Indonesian Migrant Workers Union (SBMI) is an organization that represents the interests of Indonesian migrant workers. SBMI aims to advocate for the rights of migrant workers in Indonesia, protect them from exploitation, and improve their working conditions and welfare. Through the learning and development of accounting systems, promotion management, digital marketing, and innovative product development for digital-based economic groups, the Indonesian Migrant Workers Union (SBMI) is expected to provide a good opportunity to enhance personal and family economics. The Community Service Team (PkM) from Fisipol UKI collaborated with lecturers from Pasundan University to initiate the socialization and training for migrant worker unions in Sukabumi, West Java. The PkM team focused on training participants in utilizing E-Commerce applications and the Tik-Tok social media application to market their products. Participants also engaged in direct practice of marketing products on E-Commerce and Tik-Tok applications. After undergoing direct training, participants then completed a post-test, showing significant progress with 97% of participants understanding the concept of marketing using E-Commerce and Tik-Tok. At the conclusion of the socialization and training, the UKI PkM Team provided social media accounts and phone numbers to participants for easier communication when they have questions or need assistance with product marketing.

Screening and Retaining Adolescents Recruited Through Social Media: Secondary Analysis from a Longitudinal Clinical Trial.

Social media has become a popular method to recruit participants, particularly for studies with hard-to-reach populations. These studies still face challenges in data quality and, for longitudinal studies, sample retention. However, in addition to aiding in recruitment, social media platforms can help researchers with participant verification and tracking procedures during the study. There is limited previous research describing how longitudinal studies can use social media to screen and retain participants. This paper describes strategies implemented to screen and retain a nationwide sample of sexual minority youth who were recruited through social media platforms for a longitudinal study testing a drug abuse prevention program. Our screening strategies for participants included collecting necessary demographic information (name, phone, email, and social media accounts), verifying this information using publicly available web-based records, and sending confirmation emails to ensure working email addresses and correct dates of birth. Retention strategies included communications designed to develop positive participant relationships, incentives for survey completion, regular updating of participant contact information, targeting hard-to-reach participants, and using social media as an alternative means of contacting participants. During enrollment, although the only demographic data required were a phone number and an email address, 87.58% (1065/1216) of participants provided their Instagram as an alternative means of contact. This form of alternative communication remains the most preferred with 87.40% (1047/1198) of participants continuing to provide an Instagram username as of January 2023, about 3 years after recruitment began. In comparison, other alternative means of contact (eg, Facebook and alternative email) were provided by only 6.43% (77/1198) to 56.18% (673/1198) of participants. Direct messaging on Instagram was used to successfully confirm participant identity, remind participants to take annual follow-up surveys, and update lost participant contact information. Screening and retention strategies used in the study have helped achieve 96.30% (1171/1216) to 96.79% (1177/1216) sample retention across 3 waves of data collection. Though social media can be a helpful tool to recruit participants, attrition and participant authenticity difficulties may be associated with this method. Screening and retention strategies can be implemented to improve retention. Internet searches are effective for screening youth to ensure they meet eligibility requirements. Additionally, social media-Instagram in this study-can help to track and locate participants who do not respond to traditional contact methods. ClinicalTrials.gov NCT03954535; https://clinicaltrials.gov/study/NCT03954535.