Article type
Year
Abstract
Background: it is well-known that the number of published articles has increased dramatically during the last decade. The experience from conducting health technology assessments (HTA) at the HTA-centrum in Region Västra Götaland during a nine-year period, gives an impression of an increase in the number of hits from the literature searches. It is however uncertain whether the increased publication rate also has resulted in more included articles.
Objectives: we aimed to investigate whether the number of search hits has increased over time and if there is a corresponding increase in the number of included articles in the HTAs. We also aimed to explore potential explanations.
Methods: we reviewed all HTAs conducted during 2010 to 2018. We excluded updates and reports based on a previous systematic review (SR) and subsequent original articles. We extracted data from the PRISMA flow chart regarding the number of unique hits and the number of finally included articles. We also recorded the number of PICOs (population, intervention, comparison, outcome) in the research question and number of databases searched. We categorized the key search terms as specific or non-specific. We included as explanatory variables in linear regression analyses with unique hits and number of included articles, number of PICOs and databases, as well as specific search terms and calendar year as two different dependent variables.
Results: a total of 80 HTAs were published during the study period, and 71 fulfilled the inclusion criteria. The mean number of search hits increased by 120% over time; from 848 (SD 531; range 193 to 2067) in the first two years, to 1862 (SD 1154; range 544 to 4639) at the end of the study period (2017-2018). The mean number of finally included articles was 15 (SD 6; range 7 to 30) in the first period, and increased by 68% to 26 (SD 24; range 2 to 70) in the last period. In the linear regression analyses, only calendar year was associated with the number of unique hits, while only the number of PICOs was associated with the number of finally included articles.
Conclusions: the number of search hits per HTA has more than doubled over a nine-year period, while the number of finally included articles has increased to a lesser extent. The work load in conducting a SR/HTA has thus increased both regarding the number of titles/abstracts to screen and the number of articles to assess. Neither the number of PICOs, databases or specific key search terms was significantly associated with an increase in unique search hits, suggesting that limiting these factors may not have a major impact on the result of the search process.
Patient or healthcare consumer involvement: we have only recently started to invite patient representatives in our HTA process to contribute their viewpoint in the PICO discussion. Therefore, no conclusions can be drawn regarding potential impact of patient involvement on literature search hits so far.
Objectives: we aimed to investigate whether the number of search hits has increased over time and if there is a corresponding increase in the number of included articles in the HTAs. We also aimed to explore potential explanations.
Methods: we reviewed all HTAs conducted during 2010 to 2018. We excluded updates and reports based on a previous systematic review (SR) and subsequent original articles. We extracted data from the PRISMA flow chart regarding the number of unique hits and the number of finally included articles. We also recorded the number of PICOs (population, intervention, comparison, outcome) in the research question and number of databases searched. We categorized the key search terms as specific or non-specific. We included as explanatory variables in linear regression analyses with unique hits and number of included articles, number of PICOs and databases, as well as specific search terms and calendar year as two different dependent variables.
Results: a total of 80 HTAs were published during the study period, and 71 fulfilled the inclusion criteria. The mean number of search hits increased by 120% over time; from 848 (SD 531; range 193 to 2067) in the first two years, to 1862 (SD 1154; range 544 to 4639) at the end of the study period (2017-2018). The mean number of finally included articles was 15 (SD 6; range 7 to 30) in the first period, and increased by 68% to 26 (SD 24; range 2 to 70) in the last period. In the linear regression analyses, only calendar year was associated with the number of unique hits, while only the number of PICOs was associated with the number of finally included articles.
Conclusions: the number of search hits per HTA has more than doubled over a nine-year period, while the number of finally included articles has increased to a lesser extent. The work load in conducting a SR/HTA has thus increased both regarding the number of titles/abstracts to screen and the number of articles to assess. Neither the number of PICOs, databases or specific key search terms was significantly associated with an increase in unique search hits, suggesting that limiting these factors may not have a major impact on the result of the search process.
Patient or healthcare consumer involvement: we have only recently started to invite patient representatives in our HTA process to contribute their viewpoint in the PICO discussion. Therefore, no conclusions can be drawn regarding potential impact of patient involvement on literature search hits so far.