Challenges of one-year longitudinal follow-up of a prospective, observational cohort study using an anonymised database: recommendations for trainee research collaboratives

BMC Med Res Methodol. 2019 Dec 12;19(1):237. doi: 10.1186/s12874-019-0857-y.

Abstract

Background: Trainee research collaboratives (TRCs) have pioneered high quality, prospective 'snap-shot' surgical cohort studies in the UK. Outcomes After Kidney injury in Surgery (OAKS) was the first TRC cohort study to attempt to collect one-year follow-up data. The aims of this study were to evaluate one-year follow-up and data completion rates, and to identify factors associated with improved follow-up rates.

Methods: In this multicentre study, patients undergoing major gastrointestinal surgery were prospectively identified and followed up at one-year following surgery for six clinical outcomes. The primary outcome for this report was the follow-up rate for mortality at 1 year. The secondary outcome was the data completeness rate in those patients who were followed-up. An electronic survey was disseminated to investigators to identify strategies associated with improved follow-up.

Results: Of the 173 centres that collected baseline data, 126 centres registered to participate in one-year follow-up. Overall 62.3% (3482/5585) of patients were followed-up at 1 year; in centres registered to collect one-year outcomes, the follow-up rate was 82.6% (3482/4213). There were no differences in sex, comorbidity, operative urgency, or 7-day postoperative AKI rate between patients who were lost to follow-up and those who were successfully followed-up. In centres registered to collect one-year follow-up outcomes, overall data completeness was 83.1%, with 57.9% (73/126) of centres having ≥95% data completeness. Factors associated with increased likelihood of achieving ≥95% data completeness were total number of patients to be followed-up (77.4% in centres with < 15 patients, 59.0% with 15-29 patients, 51.4% with 30-59 patients, and 36.8% with > 60 patients, p = 0.030), and central versus local storage of patient identifiers (72.5% vs 48.0%, respectively, p = 0.006).

Conclusions: TRC methodology can be used to follow-up patients identified in prospective cohort studies at one-year. Follow-up rates are maximized by central storage of patient identifiers.

Keywords: Follow-up; Methodology; Research collaborative; Surgery.

Publication types

  • Multicenter Study
  • Observational Study

MeSH terms

  • Aged
  • Data Collection / methods
  • Data Collection / statistics & numerical data
  • Databases, Factual / statistics & numerical data*
  • Digestive System Surgical Procedures / methods
  • Digestive System Surgical Procedures / statistics & numerical data*
  • Education / methods
  • Education / standards
  • Education / statistics & numerical data*
  • Female
  • Follow-Up Studies
  • Guidelines as Topic / standards
  • Humans
  • Longitudinal Studies
  • Male
  • Middle Aged
  • Outcome Assessment, Health Care / methods
  • Outcome Assessment, Health Care / statistics & numerical data*
  • Prospective Studies