Loneliness and Social Isolation in the United States, the United Kingdom, and Japan: An International Survey

The Kaiser Family Foundation/The Economist Loneliness and Social Isolation in the United States, the United Kingdom, and Japan: An International Survey was conducted among nationally representative random digit dial (RDD) telephone (landline and cell phone) samples of adults ages 18 and older, living in the United States (including Alaska and Hawaii), in the United Kingdom, and Japan (note: persons without a telephone could not be included in the random selection process). SSRS carried out the sampling and weighting for all countries, and conducted computer-assisted telephone interviews for the U.S. sample. Interviews in the U.K. were carried out by GDCC and interviews in Japan were carried out by Adams Communications, under the direction of SSRS. RDD landline and cell phone samples were provided by Marketing Systems Group (MSG) for the U.S., Sample Solutions Europe (SSE) for the U.K., and Adams Communications for Japan. Interview languages, field dates, and sample sizes for each country are shown in the table below. Teams from The Economist and the Kaiser Family Foundation worked together to develop the survey questionnaire and analyze the data. The Kaiser Family Foundation paid for the fieldwork costs associated with the survey. Each organization is responsible for its content.

Country	Field Dates	Language(s)	Total sample size (unweighted)	Cell phone sample	Landline sample
United States	April 18-May 23, 2018	English and Spanish	1,003	720	283
United Kingdom	April 18-May 23, 2018	English	1,002	503	499
Japan	April 18-June 4, 2018	Japanese	1,000	635	365

Due to the multi-national design, the questionnaire was tested and translated in multiple stages. The first step involved a live-interview telephone pretest of the English questionnaire with U.S. and U.K. respondents. Revisions to the English questionnaire were made following the pretest in order to shorten the survey instrument and improve respondent comprehension of questions. Following the English pretest, the questionnaire was translated into Spanish (for interviewing in the U.S.) and Japanese. Translations were reviewed by a team of professional translators. A second pretest was conducted in Japan after which further revisions were made to the questionnaire.

In order to better understand the views and experiences of those personally experiencing loneliness or social isolation, the full sample includes additional interviews with people who say they “always” or “often” feel lonely, that they lack companionship, isolated, or left out (commonly referred to as an “oversample”). For brevity, throughout this report, this group is referred to as “lonely.” In order to complete at least 200 interviews in each country with adults meeting this definition, some interviews were only completed if the individual met the loneliness screening criteria. In the U.S., the SSRS Omnibus (weekly, RDD landline and cellular phone surveys of the general public) was used to identify respondents who qualified as lonely and then those individuals were re-contacted and re-screened for this survey. A total of 86 interviews in the U.S. were conducted with these pre-recruited individuals.

In each country, to randomly select a household member for the landline samples, respondents were selected by asking for the adult male or female currently at home who had the most recent birthday based on a random rotation. If no one of that gender was available, interviewers asked to speak with the adult of the opposite gender who had the most recent birthday. For the cell phone samples, interviews were conducted with the adult who answered the phone.

Multi-stage weighting processes were applied separately for each country to ensure an accurate representation of each country’s national adult population. The first stage of weighting involved corrections to account for the fact that respondents with both a landline and cell phone have a higher probability of selection as well as accounting for oversampling of lonely respondents, as well as non-response adjustment. The second weighting stage was designed to make demographic adjustments to the sample to match national population estimates. In the U.S., the sample was balanced to match known adult-population parameters using data from the Census Bureau’s 2016 American Community Survey (ACS) and phone use parameters from the January-June 2017 early release estimates for the National Health Interview Survey. The weighting parameters used for the U.S. were age, gender, education, race/ethnicity, census region, and telephone use. Population parameters for the U.K. were from the mid-2014 U.K. Census Update and included gender, age, educational attainment, and region as well as phone status (cell phone only or reachable by landline) from Q1 2015 Communications Market Report. Population parameters from Japan were from the Population Census of Japan 2010 and included gender, age, educational attainment, marital status and region. In the final weighting stage, the lonely oversample was weighted to reflect its actual share in the adult population for each country. All statistical tests of significance account for the effect of weighting.

At the end of the field period, SSRS completed several data validation processes on the international data that included: internal validity checks, testing for straightlining, and analyzing paradata (interviewer workload, interview length, interview time, and overlap of interviews). The Kaiser Family Foundation, along with SSRS, also conducted a percent-match procedure to identify cases that share a high-percentage of identical responses to a large set of questions. This extra validation measure allows for detection of possible duplicate data, whether as a result of intentional falsification, or due to errors in data-processing.

The margin of sampling error including the design effect for each country sample is shown in the table below. For results based on subgroups, the margin of sampling error will be higher; sample sizes and margins of sampling error for subgroups are available by request. Note that sampling error is only one of many potential sources of error in this or any other public opinion poll. Kaiser Family Foundation public opinion and survey research is a charter member of the Transparency Initiative of the American Association for Public Opinion Research.

Country	Total sample size (unweighted)	M.O.S.E
United States
Total	1,003	±3 percentage points
Total reporting loneliness or social isolation	276	±7 percentage points
United Kingdom
Total	1,002	±4 percentage points
Total reporting loneliness or social isolation	261	±4 percentage points
Japan
Total	1,000	±4 percentage points
Total reporting loneliness or social isolation	200	±9 percentage points