Idiopathic sudden sensorineural hearing loss (ISSNHL) is an ENT crisis defined as an unexplained unilateral sensorineural hearing impairment of at least 30 dB across three contiguous frequencies occurring within a 72-hour period.^[1] It affects around 0.005 % to 0.027 people in a year, this condition necessitates proper medical intervention to prevent  auditory deficits and unseen reduced quality of life. While the exact cause is unknown, certain hypothesis suggest vascular occlusion, viral cochleitis, and autoimmune conditions as primary drivers of cochlear damage.^[1]

Corticosteroids remain the keystone of primary treatment due to their potent anti-inflammatory effects and their ability to restore endolymphatic homeostasis.^[2] Generally, the standard regimen has been a high-dose systemic oral steroid in tapered dose (OST), usually involving prednisolone or prednisone.^[3] While, the inner ear is guarded by blood-labyrinthine barrier (BLB), it limits concentration of systemic drugs reaching the desired organ. Hence, intratympanic steroid (ITS) injections have gained widespread popularity, as they are injected directly into the middle ear for diffusion across the round window membrane, achieving desired cochlear perilymph concentrations up to 100x higher than systemic administration.^[4]

Recent large-scale randomized trials and meta-analyses have shown that ITS is higher than oral prednisone in terms of pure tone average (PTA) recovery.^[3] Despite of this known efficacy, hearing result in regular practice remain highly unpredictable. A critical epistemological gap exists between "efficacy"—performance under the monitored conditions of a trial—and "effectiveness," which describes how a protocol performs in real-world clinical reality. While clinical trials assume perfect compliance, real-world effectiveness is fundamentally compromised by the "attrition of compliance".^[1]

High-dose of oral steroids are linked with a high "metabolic cost" for hearing outcomes, including systemic adverse effects such as hyperglycemia, severe insomnia, mood lability, and gastrointestinal distress.^[5] These side effects result in low compliance; current literature indicates that compliance rates for OST are significantly lower (83.5%) compared to ITS protocols (97.8%).^[1] Patients on oral regimens frequently encounter a "critical debilitating period" around 5^th Day, where the drug toxicity of the steroid leads to premature cessation.^[1] In contrast, ITS offers a "assured delivery" model because the burden of administration shifts from the patient to the clinician.

The main aim of our study was to perform a comparative analysis of patient compliance rates and clinical outcomes between OST and ITS protocols. By identifying the predictors of non-compliance—such as advanced age and pre-existing diabetes—and quantifying the resulting audiometric "cost," this research aims to refine treatment selection to maximize the potential for cochlear rescue. Understanding compliance is vital to distinguishing between a biologically steroid-resistant cochlea and a metabolically intolerant patient.^[1]

OBJECTIVES^[1]

• To study discrepancies in compliance between the two regimen, testing the hypothesis that ITS regimen achieve better completion rates due to the shifting of the administration burden from the patient to the clinician.
• To identify independent predictors of non-compliance, such as advanced age (>60 years) and pre-existing metabolic comorbidities like diabetes mellitus, which may exacerbate systemic steroid toxicity.
• To evaluate the audiometric "cost" of non-compliance by comparing Pure Tone Average (PTA) improvements between compliant and non-compliant patient cohorts to determine the threshold at which medication abandonment compromises cochlear rescue.
• To identify the "critical debilitating period"—the specific timeframe during an oral taper when systemic adverse effects, such as hyperglycemia and insomnia, typically lead to premature cessation.

Study Design: Retrospective cohort design Study group :The study population included 183 adults (aged 18–60 years) diagnosed with unilateral ISSNHL of ≥30 dB across at least three contiguous frequencies occurring within 72 hours and presenting to ENT OPD. Inclusion Criteria: Adults of both sexes (aged 18–60 years) diagnosed with unilateral ISSNHL with initiation of treatment within 7 days of symptom onset and a minimum follow-up of 2 months. Exclusion Criteria: Patients with hearing deficit like Meniere’s disease , ototoxicity, vestibular schwannoma, or trauma Patient taking simultaneous treatment of systemic and local steroid drug, Fluctuating hearing loss, Pre-existing profound hearing deficits in the contralateral ear. Patients above the age of 60years were excluded to reduce the confounding effects of presbycusis.[1] Methodology Data were collected from clinical files of patients treated for idiopathic sudden sensorineural hearing loss (ISSNHL) at our centre. Patients were divided into two primary treatment cohorts based on shared decision-making that weighed patient comorbidities and preferences: 1. Group 1: Patients were given prednisolone (1 mg/kg/day, max 60 mg) as a single dose in morning for 7 days, followed by a 7-day tapering course, totalling 14 days of treatment.[1] 2. Group 2: Patients were given four injections of dexamethasone (10 mg/ml) directly into the tympanic cavity via tympanic membrane, two times a week for two-weeks.[1] Injections were given using a 26-gauge needle into middle ear via a posteroinferior quadrant of tympanic membrane under local anesthesia (10% lidocaine).[4] Compliance was defined differently for each modality to reflect the burden of administration: • Group 1 Compliance: patient has taken ≥75% of the prescribed total dose, verified via pharmacy refill records and patient file. "Non-compliance" was defined as patient taking <75% of the dose or premature stopping (treatment lasting <7 days).[1] • Group 2 Compliance: patient has completed all four prescribed injection. Since this modality shifts the burden of administration from the patient to the clinician, it was categorized as "assured delivery" once the patient attended the clinic.[1] Hearing evaluation and result Measures : Hearing improvement was evaluated using Pure Tone Average (PTA), and the arithmetic mean of thresholds at 0.5, 1, 2, and 4 kHz was taken.[1] • Primary Outcome: The discrepancy in compliance between the group 1 and group 2.[1] • Secondary Outcomes: Mean PTA improvement (dB) at 2 months and recovery categorization based on Siegel’s criteria (Complete: final hearing better than 25 dB; Partial: >15 dB gain and final hearing 25–45 dB; Slight: >15 dB gain and final hearing >45 dB; No Improvement: <15 dB gain).[6] Statistical Analysis : Data were analyzed using multivariate logistic regression to identify independent predictors of non-compliance, such as age (>60 years), diabetes mellitus, and initial PTA severity.[1] Independent t-tests or Mann-Whitney U tests were used to compare mean PTA gains between compliant and non-compliant cohorts. A segmented linear regression was further utilized to identify a "breakpoint" in treatment latency, exploring how delays in administration affected recovery status. All tests were two-tailed with α set at 0.05.[5]

Out of 211 individuals, around 183 patients were included in the study. 28 patients were excluded because they did not meet inclusion criteria .The group 1 included 91 patients who had received OST, and the group 2 included 92 patients who had received ITS. Among 91 patients in group 1 only 76 patients were compliant to treatment rest 15 prematurely terminated their treatment due to systemic side effects. Among 92 patients in group 2, around 90 patients were compliant whereas 2 people were non compliant.

A

The major discrepancies was observed in treatment compliance between the two delivery modalities. In the intratympanic steroid (ITS) group, the compliance rate was 97.8% (90 of 92 patients). In contrast, patients receiving oral steroid therapy (OST) demonstrated a significantly lower compliance rate of 83.5% (76 of 91 patients). Multivariate analysis indicated that the odds of adhering to an ITS protocol were more than seven times higher than adhering to an oral taper (OR: 7.09; 95% CI: 2.21 to 19.02; p<0.001).

Among patients who failed to complete the oral steroid course, the mean duration of therapy before cessation was 5.1 ± 1.1 days. The primary reasons for premature cessation of OST included:

• Hyperglycemia or uncontrolled diabetes: 27%.
• Severe insomnia or psychiatric disturbance: 21.5%.
• Gastrointestinal intolerance (dyspepsia/gastritis): 29%.
• Palpitations or elevated blood pressure: 15.6%.

Independent predictors of poor OST compliance identified via multivariate logistic regression were age >60 years (OR: 3.2; 95% CI: 1.5-8.1; p=0.03) and a pre-existing diagnosis of diabetes (OR: 3.9; 95% CI: 1.2-14.7; p=0.007).

Compliance was a primary determinant of hearing improvement within the oral therapy cohort. Compliant OST patients achieved a mean Pure Tone Average (PTA) improvement of 23.7 dB, whereas non-compliant patients achieved only 13.6 dB(p=0.003). Compliant OST patients were more likely to achieve complete or partial improvement compared to non-compliant individuals (56.7% vs. 24.3%; OR: 2.98; p=0.003). Notably, there was no statistically significant difference in recovery rates between compliant OST patients and the ITS group (p=0.45), supporting the physiological superiority of the oral regimen when completion is achieved.

Large-scale randomized data confirmed that ITS is superior to oral prednisone, with mean PTA improvements of 26.8dBfor ITS and 28.6dB for OST at 2 months. However, treatment efficacy was heavily dependent on timing. Segmented linear regression identified a critical breakpoint of 18 days from symptom onset; ITS efficacy significantly diminished if initiated beyond this window (p < 0.001).^[5] Combination therapy (concurrent OST and ITS) frequently yielded the highest recovery rates, with some studies reporting mean gains of 40 dB to 44 dB compared to monotherapy.^[2]

The safety profiles differed by modality:

• Group 1: Predominantly systemic effects, including mood changes (21.5%), sleep disturbances (32.5%), and appetite changes (20.5%). Serious events included myocardial infarction and cerebral hemorrhage.^[3]
• Group 2: Predominantly local effects, most notably ear pain (45.6%) and transient vertigo/dizziness (25.9%). Persistent tympanic membrane perforation occurred in 3.1% of patients. Injection site pain was a cited reason for withdrawal in 1.1% of the ITS population.^[3]

• The management of idiopathic sudden sensorineural hearing loss (ISSNHL) is frequently described as a "race against time". The gold standard treatment for ISSNHL is corticosteroids therapy, but the debate arises about the effective mode of delivery. Many studies have been done in past comparing the efficacy of OST and ITS regimen but very few data are present stating the importance of patients compliance in hearing improvement. Our study highlights a very important but often ignored factor that plays a pivot role in hearing outcome.[1] • The current study finds a major discrepancy in compliance between the two delivery modalities. Present study indicates that patients receiving intratympanic steroid (ITS) injections demonstrate a significantly higher compliance rate (97.8%) compared to those prescribed a high-dose oral steroid therapy (83.5%). This discrepancy is mainly due to the systemic side effects in oral therapy. To breach the blood-labyrinthine barrier (BLB) very high oral doses needs to be given, which usually jeopardise glucose mechanism and circadian rhythms. In our study, oral steroid therapy (OST) non-compliance was mainly due to hyperglycaemia (27%), severe insomnia or psychiatric disturbance (21.5%), and gastrointestinal distress (29%).[1] • Our study identified a highly specific "critical debilitating period" at approximately Day 5 of oral therapy, with the mean time to cessation being 5.1 days. This suggests that the systemic toxicity of high-dose prednisolone reaches an intolerable threshold just before the one-week mark. In contrast, ITS offers a "assured delivery" model because the burden of administration shifts from the patient to the clinician; once the patient arrives at the clinic, the drug is delivered directly to the desired region.[1] • The clinical "cost" of poor compliance is measurable and high. Compliant OST patients achieved a mean Pure Tone Average (PTA) improvement of 23.7 dB, whereas non-compliant patients achieved only 13.6 dB—a difference of over 10 dB. Crucially, when compliance is maintained, oral steroids are equally effective as ITS, supporting the better conclusions of large-scale randomized trials. This suggests that many cases documented as "steroid-resistant" SSNHL may actually represent "silent treatment failure" due to premature treatment cessation.[1] • These findings support a shift toward "precision otology," where treatment selection is matched to a patient’s metabolic phenotype. We identified age >60 years and a pre-existing diagnosis of diabetes as independent predictors of poor OST compliance. Patients with these risk factors are physiologically ill-suited for high-dose systemic tapers and should be considered for primary ITS to ensure reliable drug delivery. For those initiated on oral therapy, we propose a "Day 5 toxicity check" to identify intolerance early and transition the patient to salvage ITS before the therapeutic window for cochlear rescue permanently closes.[1] • While ITS ensures delivery, it is less convenient, requiring repeated office visits and 30-minute periods in a supine position. [3] Additionally, the timing of intervention remains of greatest importance; ITS efficacy significantly diminishes if initiated beyond 7 days following symptom onset.[5] Although this study focused on monotherapy, it is worth noting that combination therapy (concurrent OST and ITS) frequently yields the highest recovery rates (often exceeding 40 dB gains), potentially due to better penetration of the inner ear.[2]

Compliance plays an important role in hearing outcomes in Idiopathic sudden sensorineural hearing loss. Doctors must identify intolerant or poor compliant patients early so that the clinician can decide the treatment protocol by customising it according to patients demographic profile, thus increasing the scope for auditory improvement.

1. Poojary SC. Impact of patient adherence to oral versus intratympanic steroid protocols on hearing outcomes in sudden sensorineural hearing loss. Int J Otorhinolaryngol Head Neck Surg. 2026;12(4).
2. Alosaimi SM, Alotaibi NE, Malek AI, et al. Systemic Corticosteroids versus Intratympanic Corticosteroids as Primary Treatments for Idiopathic Sudden Sensorineural Hearing Loss: A Systematic Review and Meta-Analysis. Ear, Nose & Throat Journal. 2026.
3. Rauch SD, Halpin CF, Antonelli PJ, et al. Oral vs intratympanic corticosteroid therapy for idiopathic sudden sensorineural hearing loss: a randomized trial. JAMA. 2011;305(20):2071-2079.
4. Kalra H, Khare P, Kumar S. Comparative Study to Determine Role of Oral, Intratympanic, Combined Oral and Intratympanic Steroid Therapy in Idiopathic Sudden Sensorineural Hearing Loss. Int J Acad Med Pharm. 2024;6(6):872-875.
5. Kennedy DJ, Williams E, Wolf L, et al. Intratympanic steroid administration and predictors of recovery in sudden sensorineural hearing loss. PLoS One. 2025;20(10):e0332809.
6. Siegel LG. The treatment of idiopathic sudden sensorineural hearing loss. Otolaryngol Clin North Am. 1975;8(2):467-73

Funding: No funding received

Conflict of interest: None declared

Ethical committee approval: The study was approved by the Institutional Ethics Committee