Problematic mobile phone use: Validity and reliability of the Problematic Use of Mobile Phone (PUMP) Scale in a German sample

BACKGROUND: Mobile phones are ubiquitous in everyday life. Scientific studies on the problematic use of mobile phones have given initial indications of negative consequences, such as increased depression and anxiety rates and reduced sleep quality. The Problematic Use of Mobile Phone (PUMP) scale is a well evaluated, 20-item questionnaire, but a German version of the scale is still lacking. METHOD: An online sample (n = 723, age 27.8 ± 11.2 years, 25.2% men) completed a German translation of the PUMP scale (PUMP-D). We conducted standard item analyses and calculated internal consistency and retest reliability. An exploratory (EFA) and a confirmatory factor analysis (CFA) were conducted using a random split of the sample, and correlations with the self-estimated time of mobile phone usage and a global self-rating of patterns of problematic use were computed. Additionally, a second sample (n = 256, age 25.0 ± 8.8 years, 34.0% men) completed the paper version of the PUMP-D scale twice to determine the 14-day retest reliability. RESULTS: The item-total correlations ranged from r = 0.35 (p < 0.001) to r = 0.75 (p < .001). The internal consistency was α = 0.90. The self-estimated time of usage correlated with the total value of the PUMP-D scale at r = 0.50 (p < .001). The EFA resulted in a single factor, which explained 36% of the variance. The CFA of the showed a moderate fit. The two-week retest reliability in the second sample was r(tt) = 0.87 (p < .001). DISCUSSION: The German translation of the PUMP-D demonstrated a single factor structure, good psychometric properties and can be used in further research.