Pain Duration and Sleep Disruption Outweigh Opioid Dose in Postoperative Distress Across Seven Asian Regions

More than four in ten surgical patients across seven Asian regions reported moderate-to-severe anxiety on the first day after surgery, and more than one in four reported moderate-to-severe helplessness, according to a retrospective analysis of 6,105 patients in the PAIN OUT ASPIRE registry published in BioPsychoSocial Medicine. The study, led by Yuchang Bao and Chi Wai Cheung of the University of Hong Kong with colleagues including Hung Chak Ho of City University of Hong Kong, found that how long patients spent in severe pain and how badly pain disrupted their sleep were far stronger predictors of psychological distress than the sheer severity of their pain or the amount of opioid they received.

The registry data came from 25 tertiary hospitals in Indonesia, Singapore, Hong Kong, Malaysia, Saudi Arabia, the Philippines, and Chinese Mainland, collected during a one-year project in 2018. Patients aged 18 or older who were on postoperative day 1, had returned to the ward for at least six hours, underwent intraoperative procedures, had no cognitive impairment, and consented to the survey were eligible. Of 9,130 patients initially recorded, 6,105 remained after the researchers excluded those with missing pain evaluations, missing opioid dosage information at any of four perioperative stages, or missing demographic details such as age, sex, or body mass index.

The team converted opioid doses from the preoperative, intraoperative, recovery room, and ward stages into oral morphine equivalents, using conversion factors synthesized from clinical guidelines and professional societies across Europe, Australia, the United Kingdom, Canada, and the United States. Postoperative outcomes were captured with the International Pain Outcomes Questionnaire, an 11-point instrument covering psychological distress, pain intensity, pain interference, and side effects including nausea, drowsiness, itching, and dizziness. Items were categorized as mild or none, moderate, or severe using a computed ABC analysis, and the mild or none level served as the reference category in all models.

Separate multinomial logistic regressions were run for postoperative anxiety and postoperative helplessness, each adjusted for sex, age, BMI, and type of surgery, with the other distress measure included as a covariate. Odds ratios were reported with 95% confidence intervals, and p-values were adjusted for multiple testing using the false discovery rate method. Variance inflation factor analysis confirmed no serious multicollinearity, although maximum pain sat marginally below the threshold at 4.963 in the anxiety model and 4.770 in the helplessness model.

The descriptive picture was striking. Severe postoperative helplessness was reported by 15.5% of participants and severe anxiety by 19.1%, while moderate helplessness and anxiety were reported by 12.4% and 23.5% respectively. Combining moderate and severe categories, 42.6% of patients reported moderate-to-severe anxiety and 27.9% reported moderate-to-severe helplessness. Most patients, 42.6%, reported moderate maximum pain, with 35.0% reporting mild or no pain and 22.4% severe pain. For minimum pain, 59.4% reported mild or none, 27.9% moderate, and 12.7% severe. Most patients, 51.4%, experienced only a short phase of time spent in severe pain.

Time spent in severe pain emerged as the strongest correlate of anxiety. A moderate phase of prolonged severe pain was associated with an odds ratio of 2.711 for moderate anxiety and 2.295 for severe anxiety, both large effects. Maximum pain was less predictive: only severe maximum pain was significantly associated with severe anxiety, at an odds ratio of 2.164, and moderate maximum pain at 1.906. Moderate minimum pain raised the odds of both moderate and severe anxiety, at 1.469 and 1.378, while severe minimum pain showed no significant association with anxiety at any level. The authors conclude that the duration of severe pain, rather than pain severity itself, may be the key determinant of postoperative anxiety.

Sleep interference dominated the helplessness findings. Severe sleep interference carried an odds ratio of 3.307 for severe helplessness and 2.738 for severe anxiety, the largest effects in the study. Moderate sleep interference was associated with an odds ratio of 2.406 for moderate helplessness and 1.944 for moderate anxiety. Interference with in-bed activities, out-of-bed activities, and deep breathing or coughing also raised the odds of helplessness across severity levels, with severe out-of-bed interference reaching an odds ratio of 2.122 for severe helplessness. The authors note that surgery can suppress slow-wave sleep and that postoperative pain and the ward environment may further exacerbate sleep disruption, extending previous findings by controlling for opioid exposure, pain, and other side effects in the same model.

Common side effects were consistently linked to distress. Severe dizziness carried an odds ratio of 2.643 for severe helplessness and 2.095 for moderate anxiety, while severe drowsiness and severe itching were associated with odds ratios of 1.881 and 1.917 respectively for severe helplessness. Interestingly, moderate nausea was associated with lower odds of severe helplessness, at an odds ratio of 0.555, which the authors attribute to nausea often being accompanied by objective signs such as vomiting, making it easier for nursing staff to recognize and intervene early.

Opioid exposure showed only modest and stage-dependent associations. Higher intraoperative and ward oral morphine equivalents were associated with lower odds of moderate anxiety, at odds ratios of 0.969 and 0.976 per 10-mg increment, and lower odds of severe anxiety for intraoperative opioids at 0.982. Similar marginal reductions appeared for helplessness. Preoperative and recovery-room opioid exposure showed no significant associations with either outcome. The authors suggest that the timing of opioid administration may be as important as the total dose, noting that the duration of opioid treatment in the recovery room may be too brief to affect distress, and that excessive opioid use can lead to negative effects and increased mortality. Counterintuitively, moderate and severe maximum pain were associated with lower odds of moderate helplessness, at odds ratios of 0.679 and 0.687, a pattern the authors link to the fear-avoidance model and to externalized control beliefs arising from frequent opioid use and intensive postoperative care.

The study has important limitations. The retrospective design and single-point data collection on postoperative day 1 preclude causal inference, and voluntary hospital participation may introduce selection bias. Single-item measures of anxiety and helplessness may not capture the full complexity of these constructs, and the de-identified dataset lacked information on non-opioid analgesics, regional anesthesia, psychiatric medications, baseline psychological status, and procedure-specific invasiveness. The dataset also did not include country, region, or hospital identifiers, so between-region heterogeneity could not be examined. Cultural factors such as pain stoicism may have influenced self-reported outcomes. The authors recommend integrating brief psychological distress screening into routine postoperative day 1 assessments, prioritizing rapid resolution of prolonged severe pain episodes, proactively managing nighttime symptoms, and systematically monitoring common opioid-related side effects, while emphasizing that prospective studies are needed to confirm whether these approaches effectively reduce early postoperative distress.

Subject of Research: Associations between perioperative opioid use, postoperative pain, pain interference, side effects, and psychological distress after surgery in seven Asian regions

Article Title: Impacts of opioid use, postoperative pain, pain interference, and side effects on postoperative psychological distress: a retrospective study of the PAIN OUT registry in seven Asian regions

Article References: Bao, Y., Cheung, C. W., Huang, Y., Zaslansky, R., Painout ASPIRE Network, Meissner, W., & Ho, H. C. (2026). Impacts of opioid use, postoperative pain, pain interference, and side effects on postoperative psychological distress: a retrospective study of the PAIN OUT registry in seven Asian regions. BioPsychoSocial Medicine, 20(1), Article 10. https://doi.org/10.1186/s13030-026-00358-y

Image Credits: AI Generated

DOI: 10.1186/s13030-026-00358-y

Keywords: postoperative anxiety, postoperative helplessness, opioid use, oral morphine equivalents, PAIN OUT registry, sleep interference, pain intensity, side effects, multinomial logistic regression, Asian surgical populations, postoperative day 1, International Pain Outcomes Questionnaire