Nomophobia: An Individual’s Growing Fear of Being without a Smartphone—A Systematic Literature Review

This review examines the current literature focused on nomophobia (objectives, methodological design, main variables, sample details, and measurement methods) in the Scopus and Web of Science databases. To this end, we conducted a systematic literature review in accordance with the Preferred Reporting Items for Systematic Reviews (PRISMA) guidelines. The initial sample consisted of 142 articles, of which 42 met the inclusion criteria and were analyzed in detail. The findings show that the current research is in an exploratory phase, with a greater predominance of descriptive, nonexperimental, and cross-sectional studies that explore the prevalence of nomophobia mainly in adolescents and university students. The most widely used measurement instrument is the Nomophobia Questionnaire (NMP-Q) proposed by Yildrim and Correia. In addition, the research suggests that nomophobia negatively affects personality, self-esteem, anxiety, stress, academic performance, and other physical and mental health problems. We are therefore faced with a health problem, which negatively affects a person, causing psychological problems and physical and behavioral changes.


Introduction
Today's smartphones present great opportunities and comforts for people; at the same time, they facilitate the accomplishment of tasks and have achieved generalized popularity in the present society [1] thanks to their communicative power and people's engagement with them [2]. The users of this technology even state that it has become an extension of their body, determining both their identity and their way of being [3].
It is indisputable that these devices have become an integral part of modern life [4] and have come to produce behavioral modifications in everyday habits and actions [5]. The advance of mobile technology, given its ubiquitous nature, has meant that the smartphone has become an indispensable resource in people's lives [6].
However, in recent years, the number of problems arising from the use of smartphones has increased considerably [7]. As a result, the number of investigations into the state of the matter has increased, characterizing this phenomenon as addictive, antisocial, and dangerous [8]. Smartphone addiction is so prevalent that it is already considered to be like any other addiction to harmful substances. Therefore, it is a public health problem [9], which is why, because of the excessive use of this device [10] and the dependence that this technology generates [11], a new pathology known as nomophobia is emerging [12] and being cataloged as a clinical disorder [13].
Nomophobia is seen as a type of contemporary phobia that emerged in the digital age [14][15][16], which is expanding after the integration of the smartphone into society [17]. This term has its origin in England and sample details, and measurement tools of the included investigations. In order to do this, we carry out a systematic review in accordance with the Preferred Reporting Items for Systematic Reviews (PRISMA) guidelines [48] to test the following questions: RQ 1 To what extent is nomophobia a growing public health problem? RQ 2 To what extent are adolescents more vulnerable to nomophobia than other populations? RQ 3 What are the physical and mental health problems and behavioral changes associated with nomophobia?

Search Strategy
During October 2019 we carried out an inquiry that began with the introduction of the keyword "nomophobia" in all possible search fields (title, abstract, keywords, main text, and so on) in both Scopus and the main collection of the Web of Science (WOS, BCI, BIOSIS, CCC, DIIDW, KJD, MEDLINE, RSCI, SCIELO), and contemplating all possible outcomes in the present day. These databases contain most of the current research references and are, in turn, the most consulted by researchers and experts from different areas of knowledge [49]. No limits were given for geographic area, language, year of publication, or method used. We found 149 results (article, meeting, abstract, others). However, the final sample consisted of 42 references.

Inclusion Criteria
The 107 suppressed results were analyzed following a PRISMA protocol for systematic reviews [40].
The main objective was to analyze the articles with the greatest impact that had "nomophobia" as the central focus of their research. In the case of the sample retrieved from the Web of Science (n = 80), we deleted references that were not in the Journal Citation Reports indices (n = 36) and those that were not articles (n = 8) until we reached the final sample. Similarly, we performed this procedure in Scopus, excluding a total of 15 references that did not meet the inclusion criteria with respect to the type of publication. Thus, 91 references were analyzed, 34 of which were deleted as they were articles found in both databases. The 56 remaining records were assessed for eligibility on the basis of the abstract, and in case of doubt, the full text was read. Finally, this figure was reduced to 42 ( Figure 1) due to the fact that the main object of study was not nomophobia (n = 14) [3,6,[8][9][10]21,[50][51][52][53][54][55][56][57].

Search Strategy
During October 2019 we carried out an inquiry that began with the introduction of the keyword "nomophobia" in all possible search fields (title, abstract, keywords, main text, and so on) in both Scopus and the main collection of the Web of Science (WOS, BCI, BIOSIS, CCC, DIIDW, KJD, MEDLINE, RSCI, SCIELO), and contemplating all possible outcomes in the present day. These databases contain most of the current research references and are, in turn, the most consulted by researchers and experts from different areas of knowledge [49]. No limits were given for geographic area, language, year of publication, or method used. We found 149 results (article, meeting, abstract, others). However, the final sample consisted of 42 references.

Inclusion Criteria
The 107 suppressed results were analyzed following a PRISMA protocol for systematic reviews [40].
The main objective was to analyze the articles with the greatest impact that had "nomophobia" as the central focus of their research. In the case of the sample retrieved from the Web of Science (n = 80), we deleted references that were not in the Journal Citation Reports indices (n = 36) and those that were not articles (n = 8) until we reached the final sample. Similarly, we performed this procedure in Scopus, excluding a total of 15 references that did not meet the inclusion criteria with respect to the type of publication. Thus, 91 references were analyzed, 34 of which were deleted as they were articles found in both databases. The 56 remaining records were assessed for eligibility on the basis of the abstract, and in case of doubt, the full text was read. Finally, this figure was reduced to 42 ( Figure 1) due to the fact that the main object of study was not nomophobia (n = 14) [3,6,[8][9][10]21,[50][51][52][53][54][55][56][57].

Results
The articles included in this review were mostly written in English and published between 2010 and 2019. The majority presented results from Turkey (n = 8), followed by Spain (n = 7) and India (n = 6). The most used methods were only quantitative (n = 35), nonexperimental (n = 26), and cross-sectional studies (n = 32). Only n = 3 used mixed methods and n = 5 were developed with experimental design (Table A1). At the same time, it should be noted that seven of the articles analyzed attempts to create and/or validate a scale to measure nomophobia in different populations (Table A2). Finally, there are three literature review studies (Table A3).

Discussion
Internet, video games, and now the proliferation of smartphones are causing problems in people's health [40][41][42][43][44]. The rise of mobile technology as a means of interacting and communicating with people [4,6] has led to the emergence of nomophobia [12], cataloged as a typical pathology of the new millennium [15,16], arising from the constant and abusive use of technology [25], which leads to fear, stress, panic, and anxiety when that technology is not available [11,37,65] for communication or accessing information [32].
The analysis of the 42 articles retrieved from Scopus and Web of Science, which have satisfied the inclusion criteria delimited in the PRISMA review process, leads us to the following inferences. The included literature was mostly recent and in the exploratory phase of research, with a primacy of quantitative and cross-sectional studies with a young population (teenagers and university). The general objective of this current line of research is analyzing the prevalence of nomophobia, as well as the relationship of this disorder with the emergence of problems that affect the psychic, physical, and psychosocial development of the subject, as well as their academic performance.
In relation to the instruments reported from the literature analyzed, it has been ascertained that both the analysis tool initially designed by Yildrim and Correia [24] and its derivatives adapted to other study populations [7,14,22,27,28,34] have proven to be valid and reliable. The initial instrument proposed [24] is therefore consolidated as the most-endorsed tool to analyze nomophobia.
However, other instruments have also been created based on measurement scales and ad hoc questionnaires that have been used to obtain information on the prevalence of nomophobia and another linked to it, such as those provided by the research of [5,11,12,15,16,23,25,26,33,35,37,39,58,60,64,65], among others.
The results of the analyzed research highlight aspects of gender [26] and young age [33,60] as predictors of nomophobia. As for the students analyzed in the reported studies, especially those in health studies (nursing and medicine) have high levels of nomophobia [1,19,30,31]. In spite of this, engineering students revealed a higher index of this pathology over those of medicine [29]. In the field of education, nomophobia has a negative impact on learning outcomes and academic performance, as has been seen in several studies [2,13,18,62]. This phobia has led to medical and psychosocial disorders such as physical injuries [53] and mental disorders [20,59]. The latter generate a set of fears arising from the non-use of mobile devices [23]. It has also been found that extroverted people and people with deficits in consciousness, attention, emotional stability, and self-esteem are more likely to suffer this pathology [35,39,58].

Conclusions
Based on the results found in this work, it is concluded that nomophobia is a field of study that is currently in the early stages of research, so that most of the research is in the exploratory phase. Young people exposed to intensive and irrational use of technology are only aware of the advantages it offers and are unaware of the risks they may suffer as a consequence [51]. Therefore, a greater volume of research is needed to explore, investigate, and note which are the most determining variables that influence this contemporary pathology; evidence has shown that nomophobia is closely associated with individual mental health, internet addiction, and behavior modification. In addition, it is necessary to promote efficient and healthy use of mobile technology in learning spaces, in order to avoid the emergence of nomophobia and its consequences.
We, therefore, confirm our three initial hypotheses and can state that nomophobia is a public health problem typical of the digital age and that it is caused by an excessive fear of being without access to a smartphone. The great dependence that the current population has generated towards these devices, due to the different possibilities that they offer, makes them more and more vulnerable, with the adolescent population presenting a greater risk factor. Furthermore, due to the nature of the study and the various scientific contributions published so far, nomophobia is related to the development of personality disorders and mental, physical, educational, and social problems.
As for the limitations of the present study, there are those of systematic review studies, for which information may have been lost due to not using the correct descriptors or due to the lack of viability of covering all the databases existing at present. However, due to the novelty and specificity of the term, it was decided to introduce only the concept "nomophobia" as a search engine element. As a future line of research, it is proposed to analyze the influence of nomophobia on aspects related to people's day-to-day life, such as sleeping hours or food.   Nursing students who show high levels of nomophobia also regularly use their smartphones during their clinical practice, although they also believe it is necessary to implement policies that restrict the use of smartphones while working.
[18] India To determine the impact of nomophobia on education among SPPC (students pursuing physiotherapy course). The results confirm that there is a significant positive predictive relationship between extraversion and nomophobia. A negative predictive relationship was also found between nomophobia and the variable of consciousness. Emotional stability presents a negative predictive correlation. There is a significant negative relationship between self-esteem and nomophobia. The results suggest that the relationship between vertical collectivism and nomophobia is significant and positive, while the relationship between horizontal collectivism and nomophobia was not significant.

[37] Turkey
To examine the effect of problematic Internet use, social appearance anxiety, and social media use on nursing students' nomophobia levels.  Ad hoc questionnaire The study results showed that participants with a lower mean age felt more discomfort, anger, anxiety, and insecurity due to lack of access to smartphones and other related problems compared with other people. [

29] India
To find out the prevalence of nomophobia among smartphone-using medical and engineering undergraduates of West Bengal and to compare the nomophobic behaviors, predictors, and smartphone usage among them. Engineering students showed a higher proportion of nomophobes than medical students. A higher proportion of nomophobes between the two groups were women, those with smartphones beyond the age of 2, those with high monthly bills, and those who spend more than 4 hours a day on the smartphone.
[19] India To assess the prevalence of nomophobia in medical students. When users perceive smartphones as being extended, they are more likely to connect to devices, which, in turn, leads to nomophobia by increasing the tendency to search for phone proximity. In addition, words related to memory, self, and proximity search are, in fact, more frequent in the high nomophobia group compared with the low nomophobia group. The results determine that young users are more likely to have nomophobia and have a greater risk of it becoming pathological.
[20] Brazil To study nomophobia as a manifest behavior that might serve as an indication of a possible anxiety disorder.
Case study. Cognitive behavioral therapy (CBT) with the use of medicines.

Interviews Scales Inventories Questionnaires
Nomophobic behavior produces changes in daily habits and can reveal other aspects to be investigated, such as the presence of comorbid mental disorders. [

59] Brazil
This study describes the routine use of smartphones and investigates the appearance of possible emotional alterations or symptoms related to their use in patients with panic disorder (PD). Both groups exhibited dependence on and were comforted by having a smartphone; however, people with PD and agoraphobia showed significantly more emotional alterations as well as intense physical and psychological symptoms when they were apart from or unable to use a smartphone compared with healthy volunteers. [

5] Brazil
In this report, the authors present and discuss a hypothesis for the development, in individuals with panic disorder and agoraphobia, of dependence on his or her smartphone.
Case study. Cognitive behavioral therapy (CBT) with the use of medicines.
The patient showed significant medical improvement in his panic disorder and phobias, but there has been no change in his nomophobia. The findings showed that the OBS latent variable was correlated with all of the four NMP-Q latent variables. Mixed support was found for convergent validity, but high support was found for the divergent validity of the NMP-Q factors. This study contributes to a growing body of literature seeking to better understand the addictive nature of smartphones and takes a new perspective on addiction research and obsessiveness.  The authors found that cooperation is a characteristic that significantly reduces nomophobic levels, particularly for the two factors of smartphone addiction and negative consequences. Furthermore, Reward Dependence appears to be positively related to two of the factors involved in nomophobia, namely smartphone addiction and loss of control, suggesting a relationship between nomophobia and personality. [26] Turkey, Pakistan This study focused on examining the prevalence of nomophobia among university students; and the relationship between nomophobia, self-esteem, loneliness, and self-happiness with respect to gender and year of study of the university students in Pakistan and Turkey.
Cross-sectional, descriptive, correlational, and quantitative study with nonexperimental design 729 university students from Turkey and Pakistan.
Nomophobia Self-esteem Loneliness Self-happiness Nomophobia Questionnaire (NMP-Q) UCLA Loneliness Scale (ULS-8) Self-Happiness Scale Rosenberg' Self-Esteem Scale According to multivariate effects results, the main effect of gender on self-esteem and nomophobia was statistically significant, which indicates that differences between male and female students with respect to self-esteem and nomophobia were significant. The study demonstrated differences between Turkish and Pakistani students' scores on nomophobia, loneliness, and self-happiness were significant, while differences in self-esteem across countries were not statistically significant.
[2] India To assess the pattern of usage of smartphones and its effects on the academic performance of students  The results revealed 42.6% of young adults had nomophobia, and their greatest fears were related to communication and information access. The study also found that gender and the duration of smartphone ownership had an effect on young adults' nomophobic behaviors, whereas age and the duration of smartphone ownership had no effect The results of this study mean that a suitable tool can be applied to nursing professionals with the aim of facilitating the diagnosis of addictive behaviors in relation to the mobility of telephone use.

[7] Iran
This study aimed to confirm the construct validity of the Persian NMP-Q using Rasch and confirmatory factor analysis (CFA) models.
Cross-sectional and quantitative study. 3216 Iranian adolescents Nomophobia Nomophobia Questionnaire (NMP-Q) The authors concluded that the Persian NMP-Q can be used to assess nomophobia among adolescents. Moreover, NMP-Q users may compare their scores between genders in the knowledge that there are no score differences contributed by different understandings of NMP-Q items. [

28] Spain
Adapt and validate the scale to measure nomophobia (NMP-Q) to the Spanish context.  To examine the types of digital diseases arising from the use of social media and problematic use as a result of digitization, including nomophobia, cyberchondria, and the fear of getting lost. In English they are nomophobia; cyberchondria; FOMO (fear of missing out).

Literature review
The addiction takes them to a dead end, causing the appearance of digital diseases that lead to various psychological disorders in individuals. Additional studies on digital diseases would provide essential data on their symptoms in individuals. An overview of the literature shows that most studies examine nomophobia, FOMO, and cyberchondria as new diseases.
[65] Italy To have an overview of the existing literature, discussing the clinical relevance of this pathology, its epidemiological characteristics, the available psychometric scales, and the proposed treatment.

Literature review
The link between the new technologies and their psychopathological impact is not yet clear, and more research is needed in this field.
[17] India To provide clarity on the social cognitive effects of screen addiction, which leads to nomophobia among teenagers, and to become better informed as a researcher in order to inform others of best practices and solutions with regard to new media technology consumption

Literature review
The level of addiction has an influence on the environment with which the youth have connected. The level of addiction stands high among hostel students in many cases. Male and female respondents stand almost equal in many research articles. The present study finds out whether the teens are addicted to screen and smartphones or not and the aspects which made them use the same platform.