Lumbar interbody fusion (LIF) is a well-established surgical intervention often considered when conservative treatments fail to alleviate symptoms. The indications for LIF include degenerative disc disease, spondylolisthesis, recurrent disc herniation, spinal instability, and deformities such as scoliosis [1–3]. Success rates for LIF surgery have generally been favorable, with most patients experiencing significant improvements in pain and function. However, the presence of existing conditions, such as patient-reported allergies (PRAs) and psychiatric disorders, can potentially negatively impact these outcomes [4].

Current evidence regarding the correlation between PRAs and postoperative surgical outcomes have been controversial. Some studies have linked multiple PRAs to worse pain and disability scores [4,5], whereas others have shown that patients with more PRAs experienced improvements in postoperative pain and disability burden [6]. Nonetheless, the conflicting evidence surrounding the correlation between PRAs and postoperative outcome scores provides an avenue for further investigation.

Patients with a psychiatric history generally experience worse postsurgical outcomes compared to those without such disorders. Several studies have demonstrated that preexisting mental health conditions were associated with increased risks of postoperative complications, extended hospital stays, and higher readmission rates [6–10]. These findings underscore the importance of preoperative mental health assessment and optimization in improving surgical outcomes among patients with psychiatric disorders.

Therefore, the current study examined whether PRAs were associated with worse postoperative pain, mobility, and functional improvement following LIF. We hypothesize that patients with PRAs would experience less favorable outcomes. Clarifying this relationship could provide insights that could enhance preoperative planning, risk stratification, and postoperative management.

Our study challenges prevailing assumptions regarding the prognostic implications of PRAs in LIF outcomes. Prior spine literature has often linked PRAs with increased postoperative pain, disability, or dissatisfaction [10,12]. In our cohort, however, PRAs were not associated with worse pain (VAS), function (PROMIS/ODI), mobility (AMPAC), or complication rates. In fact, patients with PRAs demonstrated significantly greater improvements in PROMIS mental and overall health scores 1 year after surgery, with comparable physical recovery rates to patients with NKA. These findings suggest that PRAs may reflect psychosocial factors rather than exert direct biological effects on postoperative recovery. As such, the clinical significance of PRAs in preoperative risk stratification may need to be revisited.

The observation that patients with PRAs demonstrated greater improvement in PROMIS mental health scores despite a higher burden of psychiatric comorbidity warrants cautious interpretation. Importantly, our dataset did not capture details regarding perioperative care utilization, including visitation frequency, provider contact, psychological counseling, or formal mental health interventions. As such, we cannot determine whether the patients with PRA received varying perioperative management or follow-up protocols, which could directly explain these findings. Consequently, the observed association should be interpreted as hypothesis-generating rather than indicative of a causal treatment effect.

One possible explanation is that PRA status may serve as a marker for heightened symptom awareness or psychosocial vulnerability rather than exert a direct biological influence on postoperative recovery. Prior studies have linked multiple reported allergies with increased health vigilance, somatization, and psychological distress, particularly anxiety and depression [1,4,9]. In this context, patients with higher baseline psychological burden may perceive structured surgical care and standardized postoperative follow-up as particularly beneficial, resulting in greater relative improvement in patient-reported mental health over time. However, this interpretation remains speculative given that the present study failed to assess differences in care engagement.

Despite greater improvement in PROMIS mental health scores, patients with PRAs did not demonstrate superior absolute mental health scores at individual postoperative time points, nor did they exhibit differences in physical function, disability, pain, or mobility outcomes. This pattern suggests that the observed mental health improvements may reflect regression toward the mean or recovery from worse baseline psychosocial status rather than a sustained or treatment-driven advantage [11,13,14]. Prospective studies incorporating validated psychometric instruments, care utilization metrics, and standardized assessments of psychosocial support are needed to better describe the mechanisms underlying these findings.

Our findings do not support a dose–response relationship between the number of reported allergies and poorer outcomes. Unlike prior studies that linked increased PRA counts to decreased functional gains or higher dissatisfaction rates [5], our data showed no such trend. In fact, receiving operating characteristic curve analysis (area under the curve<0.600) demonstrated that PRA count had poor predictive value for achieving MCID in PROMIS or ODI scores, further challenging the notion that PRAs directly impair functional recovery (Fig. 1). This discrepancy may reflect differences in surgical complexity, institutional preoperative counseling strategies, or patient selection criteria. Although Lyons et al. [4] reported worsening ODI scores with increasing number of allergies, their cohort lacked standardized mental health metrics, potentially conflating allergy burden with unmeasured psychiatric morbidity [10]. Our data suggest that PRAs, when decoupled from psychiatric illness, did not independently hinder physical recovery.

In contrast to the limited prognostic utility of PRAs, preexisting psychiatric comorbidities emerged as a significant barrier to achieving optimal postoperative outcomes and remained a robust predictor of reduced ODI MCID attainment after correction for multiple comparisons. Although patients with PRAs had a higher prevalence of psychiatric comorbidities, inclusion of psychiatric history as a covariate during multivariate and MCID analyses demonstrated that psychiatric disorders, rather than PRA status, was the primary driver of reduced functional recovery. In our cohort, patients with documented psychiatric diagnoses demonstrated reduced odds of achieving clinically meaningful improvements in physical function, as evidenced by their lower rates of achieving the MCID for PROMIS physical (OR, 0.517) and ODI (OR, 0.273). These findings are consistent with existing studies in both arthroplasty and spine surgery, which showed that depression and anxiety were associated with a 20%–30% reduction in the likelihood of reaching functional recovery benchmarks [2,15–17]. Prior studies suggest that depression and anxiety may be particularly associated with worse postoperative outcomes; however, diagnosis-specific effects could not be evaluated in the present study and warrant further investigations [2,15–17]. Nonetheless, several mechanisms may explain this relationship, including neurobiological dysregulation involving inflammatory mediators (e.g., interleukin-6 and tumor necrosis factor-alpha), which can impair tissue healing and central pain modulation [18,19].

Behavioral and psychosocial factors, such as diminished adherence to rehabilitation protocols and reduced physical activity, may negatively affect postoperative recovery. Additionally, cognitive distortions and negative emotional states can alter pain perception and increase self-reported disability, thereby complicating clinical assessment. These results reinforce the importance of incorporating validated preoperative mental health screening tools, such as the Patient Health Questionnaire-9 (PHQ-9) and the Generalized Anxiety Disorder seven-item scale, into routine surgical risk stratification. As recommended by Enhanced Recovery After Surgery pathways, integrating behavioral health interventions, such as cognitive behavioral therapy, into perioperative care has shown early promise, with pilot studies in spine surgery reporting a 15%–25% improvement in patient-reported outcomes [1,20–22].

Neither PRA status nor allergy count significantly impacted postoperative pain (VAS), mobility (AMPAC), or surgical complications. This lack of an association between PRAs and psychiatric history and immediate postoperative metrics (i.e., AMPAC and VAS) implies that intraoperative technical success is achievable regardless of these factors. Moreover, meaningful recovery following LIF may be more closely linked to improvements in mental health outcomes. Additionally, improved engagement with healthcare providers and better postoperative monitoring may have mitigated baseline psychological distress in the PRA subgroup, thereby improving their mental health. This interpretation aligns with the growing body of evidence advocating for integrated mental health support in surgical settings to optimize recovery outcomes, particularly for vulnerable patient populations [4]. However, the long-term divergence between mental and physical outcomes highlights the need for tailored rehabilitation. For example, patients with PRAs may benefit from integrating psychological interventions into physical therapy to sustain early improvements in mental health, whereas patients with psychiatric disorders may require augmented analgesia or activity pacing.

Some limitations inherent to the retrospective design of this study should be acknowledged. First, confounding by unmeasured variables, such as socioeconomic status, health literacy, or surgeon-specific factors, cannot be overlooked. Second, although psychiatric diagnoses were included in the analysis, detailed information regarding disorder severity, treatment adherence, and psychotropic medication use was not available. Additionally, psychiatric diagnoses were analyzed as a composite variable, which precluded the assessment of whether specific conditions (e.g., depression, anxiety, and bipolar disorder) were differentially associated with postoperative outcomes following LIF. Furthermore, allergy data were not verified through allergy testing but rather relied on self-report within the electronic medical records, which may be influenced by subjective interpretation or documentation variability. Third, the generalizability of our findings may be limited considering that the study was conducted in a predominantly rural setting. Differences in patient diversity, access to care, and presentation of psychiatric comorbidities between urban and rural populations may lead to differing results. Furthermore, our data reflect only short- to mid-term outcomes, with follow-up limited to 1-year PROMs and immediate postoperative VAS and AMPAC scores. Future studies incorporating validated psychometric tools, such as the Pain Catastrophizing Scale or PHQ-9, along with biomarker profiling (e.g., cortisol and cytokine levels), could help clarify the mechanisms underlying the association between psychiatric comorbidities, PRAs, and postoperative outcomes.

PRAs were not associated with worse outcomes following elective LIF. On the contrary, patients with PRAs demonstrated greater improvements in PROMIS overall and mental health scores 1 year after surgery. PRA status did not influence postoperative pain (VAS), mobility (AMPAC), complication rates, or MCID achievement in PROMIS or ODI scores. These findings suggest that PRAs should be viewed as potential markers for underlying psychosocial needs, reinforcing the importance of holistic perioperative support and evidence-based behavioral interventions for patients with psychiatric comorbidities.